Re:Zero IF

''This page is about the Re:Zero What if Web Novel Chapters. If you're searching for the "What IF" light novel featuring the Natsuki Rem/Sloth IF story, see Re:IF. If you're searching for the "What IF" light novel featuring the Kasaneru/Greed IF story, see Re:IF Kasaneru''.

Re:Zero IF are Web Novel chapters posted on Shōsetsuka ni Narō each April Fools at 01:00 Japanese time. To celebrate Natsuki Subaru's birthday, the author writes a story that deviates from the original Web Novel. They are around four times longer than normal Web Novel chapters and in these chapters, it is shown what would have happened if Natsuki Subaru did something contrary to what he actually did. Each of the What IF stories resemble one of the seven deadly sins.

Re: Repeating Life in Another World from Zero
Published on April fools of 2016, Tappei Nagatsuki wrote a chapter, commonly known as Kasaneru or Greed IF, where Natsuki Subaru accepts Echidna's help and forms a contract with her. The actual chapter starts some time after the fifth arc.

Following the full release of all 8 BD volumes for Re:Zero's 2nd Season, the author had released a limited copy of the expanded Light Novel version of the original Kasaneru story. The Light Novel was released on the 19th of October, 2021. It's the second IF story to receive a light novel adaptation after the Rem/Sloth IF.

Summary
After Subaru made the contract with Echidna, he decided to use his Return by Death to solve all of his problems, in his goal to save everyone and eventually make Emilia into the King. With Echidna advising him, Subaru was able to take care of the problems which he faced in Sanctuary and saved everyone.

After returning by death over 100 million times and losing count, Subaru woke up as usual at Roswaal Manor on the 14th of Kissdam. He got out of bed, and after washing his face, he practised his smile in the mirror. After doing so, he visited Echidna's dream world using the pendant at his neck as per his usual routine.

After a rather blustery conversation with Echidna, Subaru returned back to the real world where he was greeted by Petra Leyte coming to wake him up. Following her wake up call, Petra expressed her concerns to Subaru about whether the weather would get worse later in the afternoon as she planned to go shopping.

After Petra's departure, Subaru's daily routine started. He first visited the mansion's courtyard to find Garfiel Tinsel and Reinhard van Astrea sparring. This was a daily occurrence for them as Garfiel aimed to grow stronger. Garfiel had been greatly affected by the events that had transpired back at the Sanctuary, and had struggled to keep the time of its liberation at bay as Subaru had tried to isolate him from the other villagers. In the end he could not avert Sanctuary's fate and he would have perished to the Great Rabbit, if Subaru and Roswaal L Mathers hadn't saved him. This resulted in Garfiel being extremely belligerent towards Subaru, joining the Emilia Camp only at his sister Frederica Baumann's request.

This time as well, Garfiel was defeated by Reinhard, and the former retired back to the mansion. Reinhard had been recruited over to the Emilia camp by Subaru after he used his Return by Death to eventually convince Felt to abandon him, leaving Reinhard emotionally broken. After Reinhard retired back to the mansion as well, Echidna speaking to Subaru as thought-waves through his pendant tried to reassure him he had made the right choice.

Continuing with his daily routine, Subaru went to visit Beatrice who had holed herself up in a room rather reminiscent of her old forbidden library which had burned down at the old Roswaal Manor. Beatrice had sunk into a deep depression as Subaru had torn her out of the library against her will during the events of Sanctuary. During his visit, Subaru tried to comfort her, but he was met by her scratching his face and neck. After leaving the imitation library, Subaru reflected on whether he had made the right choice back then, and wondered if he should have lied to her and said he was "That Person". Once again, Echidna tried to reassure him that he had made the right choice and said that with time she'd open up to him so that her emotional wounds could be healed.

As he continued to the next area of his daily routine, Subaru happened to come across Roswaal who was in high spirits. The two had a brief discussion in which Roswaal affirmed that the two of them would mutually cooperate with each other to achieve their most cherished desires. Subaru, who wasn't all too happy with being used like this, begrudgingly continued on with this day.

Subaru made his way to the room which Rem was in. She was still comatose due to Gluttony's effect. Ram was in the room on Roswaal's orders. She had been ordered to be extremely polite to Subaru, and had no real interest in her comatose sister. Subaru asked her to leave the room, which she did. Left alone with the comatose Rem, Subaru called for Echidna's help. He asked her to remind him what the ways to wake up Rem were. Echidna listed three reasons, but advised him to go for the last one which was to get the blood of the dragon by making Emilia king. Subaru pledged that no matter how many times he would die, he would wake Rem up.

Finally, Subaru arrived at the end of his daily routine, where he visited Emilia's room. Emilia was in a fragile mental state due to the fact that she couldn't surmount the trials back at the Sanctuary. She noticed Subaru's scratch marks and immediately realised they were from Beatrice. She lost control of herself and started to freeze the mansion. Subaru was able to luckily calm her down due to having practised his smile in the mirror earlier. After her outburst, Subaru told her to study for today and that he'd dine with her later. As he talked to Emilia, Echidna butted in and started to slander Emilia, continuing to do so even after Subaru left Emilia's room.

After dining with Emilia, Subaru had a flashback to when Otto Suwen left the Emilia camp one year ago. The flashback caused Subaru great distress, agonising about whether he had taken the optimum choices when he was Returning by Death. As he agonised over it, he found himself back at his room, where Elsa Granhiert was awaiting him. Elsa had joined the Emilia Camp after the events of Sanctuary and was currently entrusted with the mission of finding where Gluttony was at.

After some talk with Elsa, in which Subaru learnt that the latest location she had investigated turned out to also not have the Gluttony Archbishops, Subaru asked her what the weather was like beyond the forest. Confused by his question, Elsa replied that it looked fine. Subaru nodded and commanded her to kill him. Elsa was a bit confused by the question, but obliged, and lopped off Subaru's head.

Subaru returned by death not knowing which day he had returned to, realising his save point had changed. In a panic, he rushed to Echidna's dream world to find out what day it was. He eventually learnt from her that it was the 14th of Kissdam. Echidna realised that Subaru had used his ability to reset, and both of them steeled themselves knowing that trouble was brewing in the future that Subaru would have to confront. In addition to this, Echidna asked him why he had used his Return by Death, but Subaru declined to answer.

After leaving the dream world, Subaru was once again greeted by Petra. This time, when she voiced her concerns about whether or not the weather would be fine for when she went shopping, Subaru reassured her, and said it would. Petra found that reassuring, but asked him how he knew. Finally, Subaru answered the question by saying that it was because he had returned just for this, risking life and death.

Meanwhile, back at the dream world, Echidna was enjoying her tea reflecting on the events that had happened. She found herself fascinated by Subaru and his persistence, and declared that she'd give it her all to help Subaru protect the ones he cared about. Despite her spiel which was presented as her love of scorching flame, she voiced out a contradiction at the last: "Ah, even so-- Why does love always fade?"

Re: Erring Life in Another World from Zero
Published on April Fools of 2017, Tappei Nagatsuki wrote a chapter, commonly known as Ayamatsu or Pride IF. The point of divergence from the main story is Subaru's fourth return-by-death, where Reinhard saves Subaru from hoodlums and ultimately goes on to save him from Elsa. In this timeline, Reinhard doesn't show up to aid Subaru in the alley, as he never chooses to relegate his dignity and call for help. At the absolute rock bottom, Subaru finds that the only way he can go is up, and bound by his own pride, he resolves to "save" Emilia by any means necessary, bringing himself down a much darker path.

In Pride IF, "pride" does not necessarily refer to pride in a traditional sense, referring to a lack of humility and excess self-gratification. Contextually, pride here means unrelenting determination, even if the consequences are fatal.

Summary
The beginning of the story begins at the prologue of the main story, and the descriptions are almost identical: Subaru is on the ground writhing in pain from an unforeseen attacker inside the Loot House. His stomach is bleeding out and he is trying to scream for Emilia to run, only for her to get cut down as well. Subaru hardens his resolve to save Emilia, "No matter what." Natsuki Subaru dies his first death.

The story skips forward to his 88th revival. As Subaru begins to form his next plan to save Emilia, Ton, Chin and Kan attempt to rob Subaru once again. After fighting the three over and over again, Subaru easily learns how to kill them as efficiently as possible. Subaru leaves the alleyway and sees the familiar sight of Emilia chasing Felt through the market. Subaru just stares at Emilia, lost in thought over her beauty. He once again promises to save Emilia from her fate.

Because Subaru never meets Reinhard, he finds it impossible to beat Elsa. He can't beat her through trial-and-error, no matter how many times he revives, and so this time Subaru's plan is to direct the Capital guards to Elsa in hopes that they will either kill her or keep her preoccupied away from Emilia. Elsa turns out to be way more of a beast than Subaru anticipates, and as just he's about to leave, Reinhard arrives. As in the main timeline, Elsa is easily crushed and is forced to flee. Subaru's plan works, and his most hated enemy is on the run.

In a strange twist of fate, it's Subaru that ends up helping Elsa escape. Make no mistake, Subaru wants her dead, and Elsa can definitely sense his hatred. Despite not knowing his intent, Elsa is just fine to let Subaru lead the way. After bribing the local slum folk to misdirect the guards, the way is clear. The two make their way to Elsa's "little sister," Meili Portroute, who is waiting to tend to Elsa's wounds. From here on, Elsa and Subaru will continually make contact as allies. Subaru, who is covered in blood, heads over to the Loot house to find it frozen over. A local, who grows increasingly nervous around the disheveled Subaru, tells him that Felt and Rom have been apprehended by the guards. He stands there, proud of his work as he is approached by a group of certain individuals.

Two months go by, and Subaru is now associated with the Witch Cult. His next goal is to take down the Sin Archbishop of Sloth, Petelgeuse Romanée-Conti, and has died his 400th death in his effort. Despite having an end goal of killing him, Subaru forges a mild friendship with Petelgeuse and exchanges banter with him. After all, they both have obsessions with half-elves. Petelgeuse visits Subaru in his hideout in the middle of the Lugunican wilderness and notifies him about the ongoing Royal Election, where Subaru learns about "Satella's" real name. This, of course, makes him even more crazy for Emilia.

Then Petelguese informs Subaru of the plot to abduct Emilia to use her to resurrect Satella. Subaru, obviously not a fan, executes his own plan and stabs Petelguese with a sword, catching him completely off guard. Over the course of hundreds of years of retries, Subaru finally has a counter for everything, from the Unseen Hand to the Fingers. Even as Petelguese attempts to hijack Subaru's body, he reveals his contract with a unnamed lesser spirit of fire, and with no other options left, Petelgeuse finally dies. Subaru meets with Meili, who has presumably been working alongside Elsa to eradicate Petelgeuse's Fingers. Subaru and Meili exchange somewhat cute dialogue and they leave.

The Crusch Camp launched their battle against the White Whale, and without Subaru's actions and intelligence, it is a complete disaster. Crusch and Wilhelm are erased from history, which is all good for Subaru, because his new goal is to make Emilia queen, and the death of one candidate is ok with him. Conversely, Ferris is mentally broken by the loss of Crusch, and it doesn't take much effort for Subaru to make him subservient. Also, Subaru is working with Roswaal, who foresaw Subaru's arrival in his witch gospel. With Roswaal's aid, all credit for Subaru's actions in eliminating the Witch Cult are shifted to Emilia making her popularity with the Lugunica public explode exponentially.

In perhaps his only good act for the entire story, Subaru goes after Regulus, who is the target in his crusade against the Witch Cult. With the help of Elsa and the lesser spirit of fire, Subaru kills all of Regulus's wives by burning down his mansion, quickly disabling Regulus's authority. Elsa dismembers him until only his head and torso remains, and Regulus is left in complete shock at the thought of his wives betraying him. Subaru states the obvious, that all of them absolutely hated living as ammo for him and were happy to cooperate with Subaru's plan. Subaru then orders Elsa to throw Regulus into the fire to let him burn to death.

The Witch Cult aren't Subaru's only enemies, and we are reminded of that when he decides to murder Julius in a bar for no particular reason. For this deed, instead of Elsa or Meili, Subaru has Ferris do the killing. Julius looks on in horror as he sees one of his closest friends being ordered to kill, all while Subaru arrogantly monologues about the value of life. It is unknown what magic is used to kill Julius, but in the end, he dies of suffocation. Otto walks into the bar. In this timeline he is Russell Fellow's debt slave. This depressed Otto works to clean up Subaru's messes, even though it's clear that he absolutely loathes what he is doing. Otto even intentionally refrains from giving Subaru his name just so he can't tack it onto his murderous deeds.

Over the course of time, Subaru works to wipe out the Witch Cult, and to force all the other Royal Candidates out of the election. As he is intentionally playing the role as the villain in order to make Emilia the hero, Subaru does what is expected of him and commits a few atrocities against Lugunican citizens along the way. He is somewhat surprised, yet proud at the relationships he's come to make along the way, from the murder-happy Meili to the mysterious Roswaal. Who ever would've thought that Elsa, Meili, Roswaal, Ferris, Otto, and a random fire spirit would be the dream team, and who would've ever thought that, with the exception of Elsa and Meili, they would be so willing to commit mass murder?


 * Note: The obvious question asked here is how much influence Subaru actually has on the main story, and the answer implied is "more than we think." Despite Subaru being such an idiot for the first three arcs, it is his presence and his presence alone that decides everything, not Rem's or Ram's, not any established in-universe power's, not even Reinhard's.

With that, Subaru prepares to enact his final plot. His resolve to save Emilia is still in action, but now it is time to fight Reinhard.

Lugunica City is burning. Subaru's final plan to kill Reinhard is to make the public hate him, essentially killing "the Hero", and by having the citizens of Lugunica watch as Reinhard is unable to do anything about Subaru's atrocities, it seems that his plan has succeeded. Something that isn't mentioned is Ram's role in assisting Subaru. Because Rem dies even without Subaru's intervention as a result of Meili's demon beast, Ram is just as mentally damaged as Ferris and has no qualms about following Roswaal's order to burn down Lugunica.

Being as the Reinhard plan is pretty much a suicide mission, most of Subaru's associates are dead, probably at Reinhard's hands. When the story transitions again, Meili has just been cut down by Reinhard, an indicator at how far he's descended. Reinhard has no other goal but to be Subaru's judge, jury, and executioner. Subaru faces off with Reinhard and delivers boasts to him about thousands of times he's had to die to beat the unbeatable, and the thousands of times he's had to sacrifice others to achieve his goal.

Subaru begins to cry as he speaks, less over the remorse for sending millions to their deaths, and more over frustration at how unbeatable Reinhard is. Reinhard does not respond. He feels nothing for this crying wreck of a mass murderer, breaking down at how hard it is to kill. There is nothing more to be said, just action. Suddenly, Elsa, revealed to be still alive flies down and attacks from behind. Reinhard easily stops her blade in his palms.

Elsa experiences a flurry of emotions, looking down at Meili's corpse and looking up at Reinhard; all of them harden her resolve to save Subaru. With her final words, she tells Subaru that she enjoyed her time with him. Even if Subaru wanted her dead for a reason that may never be known, she still came to value, or dare say, love him. With that, she says her farewell.

As Subaru runs along the ruins of the burning city, he hears the shrieks and the wails of the citizens. He can take pride in himself that he, the villain, has killed the hero. He finds Meili's personal demon beast, the Guiltilaw, running about in the flames. A loyal pet as ever, Guiltilaw lifts Subaru up. With the hero dead, he only has one final goal in mind: to find the true hero who will take up the task that the old hero has failed to do. All of a sudden, multiple Huma ice pillars come flying towards Guiltilaw, and within seconds, the demon beast is dead. The real hero is here.

“—That's enough, villain.”

Emilia has another Huma cocked and loaded. Subaru can only once again stare and admire. He begins to casually talk to Emilia, even more casually than he does in the main story. Emilia, who has never met Subaru and has never spoken to him in this timeline is very obviously confused. He mentions Puck by name, which makes an even more confused yet determined Puck reveal himself.

Subaru tells her his true intention with the destruction of Lugunica, and that is to make her queen. In Emilia's eyes, all of his actions basically went unchallenged. Nobody, not even Reinhard even managed to touch him. He did it all for her.

With Emilia's realization of Subaru's true motive, he prepares to close his act. And so he declares:

“—My name is Natsuki Subaru.”

“—Witch Cult's Sin Archbishop of PRIDE, Natsuki Subaru!”

He charges Emilia (with no intent in harming her of course) and allows himself to be struck down. Emilia looks down on the wounded Subaru, while still confused and crying over what she has just heard.

Subaru is ok with it, as there is no way she can possibly understand. When Emilia asks "Why?," why he would commit so many acts of violence and murder for a person like her, Subaru briefly ponders what she wants him to answer. However, he only has one thing to say to her.

“—I love you.”

Subaru dies another death among a thousand. He is truly proud of his actions.

In the place he ends up after death, a certain being waits for him, though she is a being Subaru has not truly ever seen. She calls for him. Satisfied that he has finally "saved" Emilia, and with no more internal qualms, Subaru accepts the strangely familiar presence.

Re: Drowning Life in Another World from Zero
Published on April fools of 2018, Tappei Nagatsuki wrote a chapter, commonly known as Oboreru or Wrath IF. This time, the point of divergence happens in Arc 2, more specifically, after Rem's death. Instead of committing suicide by jumping off of the cliff, Subaru accepts Beatrice's help and proceeds to be teleported away.

Summary
The story takes place during the loop where Rem dies of the curse, or what would've been the 7th death loop. Ram goes after Subaru but he ends up surviving with Beatrice's help and runs. Ram eventually catches up to Subaru and attempts to strangle him, but collapses due to exhaustion and exposure. Subaru takes a rock and smashes her head in, beginning a long chain of violence perpetrated by him.

Two years pass. Due to the deaths of both his servants, coupled with the fact that Emilia ended up refusing to participate in the royal election, Roswaal degenerates. The spirit of Roswaal and his mansion is long gone. The few people in the mansion are Frederica Baumann, who works as the lone maid, Beatrice, Emilia, and of course Roswaal.

Subaru plots with Puck to get Emilia out of the mansion. He also has the help of Cecilus Segmunt and Halibel as his subordinates and well as various others. Cecilus cuts down Roswaal while Subaru personally kills Beatrice with a dagger after convincing her that he is her “liberator”. Frederica attempts to fight Puck and fails. However, the crew ends up sparing her and they take her back to have her work as a maid.

“Purge King” Subaru becomes an underworld boss of the brutal crime organization, Pleiades, with a base at the edge of the Kararagi border known as Pandemonium. Any who decide to oppose them are simply killed off with little regard for consequences. Subaru even takes it upon himself to decide who lives and who dies based on the flip of a coin, very literally holding the fate of his fellow men in his hands, much like a...purging king. Or a district attorney with horrific burns on half his face. Meanwhile, Emilia lives in a heavily guarded room with Puck.

Eventually, the Council of Wise Men in Lugunica discovers that Subaru is responsible for the death of Roswaal, so they send the Sword Saint Reinhard van Astrea joined with a group of what are presumably Knights to take out the “Purge King”. They plan to use the merchant Otto Suwen to disguise their attack as a business deal.

Reinhard attacks their base but is unable to reach Subaru. As Subaru already knows what danger Reinhard poses to him, Subaru keeps his best defenses (the core of which is Cecilus and Halibel themselves) close to himself and the throne. The throne had a power which absorbed Reinhard's intial attack, saving Subaru from certain death. Upon exchanging some words with Reinhard, Halibel escapes with Subaru and Cecilus fights Reinhard. Cecilus personally seeks to achieve the title of the "Heavenly Sword", believing that defeating Reinhard is the way to achieve it, and doesn't listen when the latter explains to him that the two have already fought. With a sad gaze, Reinhard unsheathes his Dragon Sword Reid, finding Cecilus to be a worthy opponent once more. They acknowledge each other, and fight for the third time in their lives.

Halibel and Subaru attempt to flee as their world actually collapses around them due to the battle between Reinhard and Cecilus destroying Pandemonium. As they’re all running, Frederica attempts to assassinate Subaru, though she fails. Subaru decides to spare her regardless (she's also implied to be the one who sold them out, but he doesn't care as someone else would've done it if she hadn't). He quickly shows her Ram's finger marks still left on his neck, and then he orders Halibel to take her and run. After that, Subaru is stabbed by Otto.

Elsewhere, Emilia decides to leave her room with Puck and encounters Reinhard, who has survived the battle but is heavily wounded. Despite hearing that Subaru is responsible for ordering the deaths of over one hundred twenty-six thousand people (126,702 to be exact), she decides to side with Subaru and attacks Reinhard with the help of Puck. It's not clear what ends up happening to Puck (the author later revealed that Puck was killed by Reinhard during the fight), but Emilia finds Subaru and tries to convince him to run with her. When he decides against it, she tells him that she'd be willing to die with him. However, this backfires immensely and causes Subaru to distrust her and abandon her. Subaru then runs back to his office where there is a secret room behind a bookcase. The sound of chains begin to ring, and Ram is shown to be chained up and still alive. She asks, "Finally, did you come wanting to die, Barusu?"

Re: Patching Together Life in Another World from Zero
Published on April fools of 2019, Tappei Nagatsuki wrote a chapter, commonly known as Tsugihagu or Gluttony IF, where Murder became a habit for Natsuki Subaru, and started to read the victim's Book of the dead during the sixth arc.

Summary
Diverging from midway through Arc 6, after Natsuki Subaru decided to enact his plan to find out who his old self, "Natsuki Subaru" was by reading everyone's books of the dead, Subaru found himself in a remote region in Northern Lugunica after slaughtering a multitude of people who knew him on his journey to cobble the pieces of himself back together. In this remote region, Natsuki Subaru kept repeating a question to Amue Sears (アミュー・シアーズ). He kept repeating "Hey, do you know my name?" to her. After some deliberation, the frightened young girl who was 14 years of age answered she didn't. Subaru, who was implied to have killed everyone else in her village, let her live.

Far prior to this event, Subaru stopped at the side of the main road to have lunch with Emilia, Beatrice, Ram, Julius Juukulius and Meili Portroute whom he had murdered back at the tower, and now appear as vivid hallucinations that speak to him quite friendly. After some lighthearted discussion with them about the perks of mayonnaise, all those individuals freeze in time, and fade from sight. In fact, Subaru only has one companion with him along the road, and that is Shaula.

As the two of them continue their journey down the main road, they meet Regin Suwen. After having realised that Regin knew the old "Natsuki Subaru", Subaru stopped to talk to him. Regin quickly realised that something was quite off with Subaru and suggested they go back to his veterinary to check if he was feeling okay. Subaru replied that he was feeling okay, though he asked if the people in the village knew him, After receiving that confirmation, Subaru commanded Shaula to kill him. She used her Hell's Snipe ability to burn off Regin's head, killing him instantly. After they hid his corpse, Subaru returned back to the Pleiades Watchtower to read his book of the dead.

Meanwhile, a short time after this, Eridna, who had been allowed to escape from the tower by Subaru, made it back to Priestella. She revealed to the members present there that she was not Anastasia Hoshin anymore, and what had transpired back at the tower. Some of the members hearing this report don't believe her, but most of them do. After this, Echidna went to talk to Ricardo Welkin, who now had a metal claw-like appendage in place of his lost arm, about her future, and how she would stop impersonating Anastasia. As they talked, the city of Priestella was flooded by Subaru and both of them perished.

After the watergates were opened in Priestella, Otto Suwen and Garfiel Tinsel both survived the initial flooding. Suddenly, beams of light poured down upon them. With great difficulty, Garfiel managed to deflect them with his shields. Subaru finally arrived at the scene, and confronted the two, and had Shaula kill Garfiel, despite the latter still not believing that his former master had gone insane.

Otto is quick to understand what had happened, and tried to distract Subaru by telling him he should have sprung a surprise attack on Reinhard van Astrea first. Subaru shook his head at that notion and said that the reason he had flooded Priestella was to kill Otto himself. Everyone else was just a bonus. Subaru understood that it would take immaculate planning to even stand a chance at defeating Reinhard. As if affirming that, the hallucinations of some of the people he had killed affirmed Subaru's plan to himself, naming Otto as the most troublesome one. After that, Otto is killed by Shaula.

Shortly after Otto's death, Reinhard confronted Subaru and gloomily asked why he was doing this. Shaula immediately commented that Reinhard gave a very Reid Astrea-like impression, grasping his immense strength immediately. Subaru had come planned for this confrontation however, and he got Shaula to cast one of her Hell's Snipe towards the shelter which Felt was staying at. This allowed Shaula to pick Subaru up and escape with him from Priestella.

Later on, after having once again visited the Pleiades Tower to read everyone he had killed's books of the dead, Subaru continued with his journey to cobble himself together to get back the old "Natsuki Subaru".

Returning back to the events after Subaru had left Amyu alive, Reinhard found the girl alive and well, though shaken. Amyu had been left behind by Subaru to delay Reinhard, who was following his trail.

Meanwhile, Subaru was talking elsewhere with Shaula. He mentioned that eventually he will have to kill Reinhard or it would be impossible to cobble himself back together. And finally, after Reinhard would be killed, Shaula would have to be the last one to die. Shaula was extremely happy to hear her master say she'd be the last one to die, taking it almost like an "I love you". Subaru was surprised at her loyalty, and asked her why she kept on doing his bidding despite knowing she'd die, and she simply replied that it was because she loved her master. Subaru's plan was that after he gathered together all the pieces, he would die and fix things with everyone after he Returned by Death and got back his old self.

The scene ended on a reflection that the pieces that would need to be cobbled together were too many, and that even if he pieced them all back together his new form would not really understand his original one.

Re: Natsuki Rem in Another World from Zero
Also known as Rem IF or Sloth IF, this story is about what would have happened if Natsuki Subaru and Rem ran away from the Kingdom of Lugunica, abandoned everything behind in the third arc, and live a family life in Kararagi. For a period of 5 years between 2014 to 2018, the author released five web novel chapters that continued the story.

The Natsuki Rem/Sloth IF was the first web novel IF story to receive a light novel adaptation called Re: Life in a Another World from IF.

The Rem:IF story is split into two main stories within the same continuity, a web novel following the Natsuki family 10 years after the events of the third arc and the official Re:IF light novel, set almost immediately after escaping the Kingdom of Lugunica. There are also several side stories related to this IF's timeline, including Fragments: Natsuki Rem, which is part of volume 9 of the light novels and Chapter 51 of the Daisanshou manga, Oni and Happiness, Fortune Roll Rhapsody and Natsuki Rigel. The story features Natsuki Subaru, Rem, Natsuki Rigel and Natsuki Spica.

Summary
For more information, see Re:IF.

Re: Zero School
This multi-chapter IF story—currently consisting of 4 parts—focuses around the characters of the series in a slice of life setting. It is also known as Vainglory IF.

Re: Mistaking Life In Another World from Zero
Published on April Fools' of 2022, Tappei Nagatsuki wrote a chapter, commonly known as Mimagau IF, which adapts the entirety of Arc 1 if everyone's gender were to be reversed. He wrote a continuation on April Fools' 2023 that adapts Arc 2.

Trivia

 * On April Fools of 2014, the author wrote The Butterfly's Dream (胡蝶之夢), commonly known as the Lust What IF chapter. It featured Subaru in a polygamous relationship with the five Royal Selection candidates, Rem, and Petra Leyte.
 * While The Butterfly's Dream was not deleted from Shousetsuka ni Narō, the chapter was edited two days later and all of its contents were replaced by a short excerpt that talks about the dream of a butterfly.
 * On August 7, 2023, the five Natsuki Rem IF chapters that were posted between 2014 and 2018 were all deleted from the main Re:Zero page on Narō, making them the first deleted Web Novel chapters. However, all five of them were reuploaded onto a separate page for Re:Zero works that are disconnected from the history of the main story.
 * Earlier in the same day, the author posted a chapter where a character's name was changed to Spica. Natsuki Spica shares the same given name as them, which potentially signifies that the author decided to move these chapters as a result of this development.

Kasaneru

 * Kasaneru IF and Rem IF are the only IF stories that have been adapted into the Light Novel format, with Kasaneru adding entire prologues and chapters-worth of content.
 * Roswaal states Annerose Miload is his next vessel, which he'll possess once his current body dies.
 * Subaru gets Garfiel out of the Sanctuary by having him fight the Oousagi by himself. Once he was overrun and almost killed, Garfiel understood his powerlessness and retreated with Subaru.
 * Echidna confirms that Clind does indeed have an Authority, though she fails to pinpoint which Authority he's in possession of.
 * When Subaru took Annerose as hostage in order to protect himself from Clind, the blue-haired butler prioritised killing Subaru over saving Annerose.
 * Subaru and Clind's fight concluded with Subaru using Frederica against him. As Clind had been shown to care about Frederica immensely, he was unable to kill her, thus being defeated.

Ayamatsu

 * Subaru was unable to use any other Authority besides Return by Death.
 * He also owned his own house, as a Witch Cultist.
 * Without Subaru's help, Crusch and her subordinates got annihilated in a fight against the White Whale. Ferris was the only survivor but due to Crusch's erasure from existence along with her memories, he broke and was unable to continue living normally. At the end, he developed a special one-sided bond with Subaru and stayed with him until his demise in the Great Fire.
 * It is unknown how many times Regulus killed Subaru.
 * The author stated that Petelgeuse was the only person in Ayamatsu who successfully invoked a friendship with Subaru. He also stated Petelgeuse was most likely the hardest Sin Archbishop for Subaru to take care of.
 * Strangely enough, Priscilla and her subordinates all mysteriously disappeared without a trace. The author later revealed that Priscilla withdrew from the Royal Selection, alongside Anastasia.
 * Due to White Whale erasing both Crusch and Wilhelm, Reinhard's relationship with his father improved. Unfortunately, Heinkel, Rom and Felt would all perish during Subaru's attack and burning of the capital.
 * According to the author, both Reinhard and Elsa were happier in Ayamatsu than in the main route.
 * Arlam Village was destroyed and all of its inhabitants were killed.
 * Rem died during Arc 2.

Oboreru

 * Despite not being shown, Subaru did in fact use Return by Death quite frequently. He had to repeat timelines in various unmentioned situation. Saving Ram from dying of Mana poisoning, gaining Halibel's trust and discovering Cecilus' goal all required excessive amounts of death and suffering on his part. Ironically, some of his deaths would include suicides, despite the point of divergence being his unwillingness to commit suicide in Arc 2.
 * Halibel joined Subaru's side to repay his actions in resolving a particular issue concerning the Four Great Spirits in Kararagi in which Subaru died many times. After that, Subaru established a power base in eastern Kararagi, building the Pandemonium where he and his subordinates remained situated for the next 2–3 years.
 * After Subaru managed to recruit Halibel, he set his goal on Cecilus. Needing a counter for Reinhard, he would die plenty before finally succeeding in recruiting him. Eventually, the Vollachian Emperor would order Cecilus to play the role of a double agent. Personally, Cecilus stood at Subaru's side in order to secure himself another battle with Reinhard. Despite common belief, Cecilus actually survived the battle with Reinhard. After the latter broke both of his katanas, Cecilus fled to live another day.
 * According to the author, he isn't sure if after Subaru's death, Emilia killed herself or attacked Ram.
 * Both Puck and Halibel died fighting against a heavily wounded Reinhard.
 * Crusch Camp suffered the exact same fate as in Ayamatsu.
 * As Emilia was absent for the entirety of the Royal Selections, the Witch Cult remained inactive in Oboreru.
 * Due to the Purge King's activity, the Four Great Countries were forced to make an exception to the "Reinhard Law" and send him to Pandemonium. He's also confirmed to have survived the incident.
 * The scene with Ram strangling Subaru happened somewhere along the Lugunican Kingdom's border with the Holy Kingdom of Gusteko.
 * Oboreru is said to last no less than 3 years.

Tsugihagu

 * Subaru's hair turned white due to the stress and shock of experiencing Beatrice's Book of the Dead. His loss of vision in his left eye occurred after he hit his head on the Tower's walls.
 * According to Tappei, Otto would likely think of an unimaginable countermeasure for Subaru's attack, so he was the most important obstacle in Subaru's plan.
 * Tappei stated he's fond of Amue Sears. He also said he'll most likely introduce her in the main story as well.
 * Out of the Royal Selection Candidates, Emilia Camp was all killed by Subaru, Anastasia camp was completely wiped out (including the members of the Iron Fang), Crusch was sent back to her mansion leaving only Ferris behind who drowned but later managed to revive himself with his ability, the Felt Camp's only victim was Rom and the Priscilla Camp left the city prematurely, so she didn't suffer any losses. It's also worth mentioning that the Selection is expected to be a one-on-one fight between Priscilla and Felt camp however, due to Rom's death, Felt lost the motivation to continue, leaving Priscilla as the winner of the Royal Selections.
 * Lye Batenkaitos and Roy Alphard were defeated by Reid Astrea, leaving Capella Emerada Lugunica the only "free" Sin Archbishop. Due to the danger Shaula and Subaru presented, she wisely kept her distance, unknowing that she was on Subaru's kill list.
 * Due to Reinhard's guilt for allowing his friend to fall so deep into the darkness, he began funding and supporting the victims of Subaru's death marches, unintentionally elevating his title as a hero.
 * At the end, Subaru never said the words Shaula wanted to hear the most.

Mimagau

 * Because everyone's gender is reversed, most of the characters in the story have different names.
 * Subaru's name remains the same.
 * Emilia is renamed to Emilio (エミリオ). Subaru adds a "-kyun" (きゅん) to his name instead of "-tan".
 * Puck is renamed to Tinkerbell (ティンカーベル), and is shortened to Tink (ティンク).
 * Satella is renamed to Luna (ルナ) and he is known as the Warlock of Envy (嫉妬の魔人 Shitto no Majin).
 * Felt is renamed to Forte (フォルテ).
 * Chin, Ton, and Kan are renamed to Ann (アン), Pon (ポン), and Tan (タン) respectively.
 * Rom's alias remains the same and is known by the nickname Old Woman Rom (ロム婆) instead.
 * Elsa is renamed to Eins (エインズ).
 * Reinhard is renamed to Adelheid (アーデルハイト).
 * Introduced in Part 2, Rem and Ram were renamed to Reu (ラウ) and Rau (レウ) respectively.
 * Beatrice is renamed to Victor (ヴィクトル). Her nicknames Betty and Beako were renamed to Vicha (ヴィーチャ) and Victa (ヴィク太) respectively.
 * Roswaal's name remains the same.
 * Petra is renamed to Pietro (ピエトロ).
 * Meili is renamed to Maoro (マォロ).