Roswaal L Mathers (ロズワール・L・メイザース) is the lord of the Roswaal Mansion, margrave of the Mathers territory, and the Dragon Kingdom of Lugnica's Court Mage. In actuality, though, he has been possessed by the soul of his ancestor, Roswaal A Mathers (ロズワール・A・メイザース) since he was 14 years old. He is one of the main supporting characters of Re:Zero, as well as the true antagonist of Arc 1 and Arc 4.
Although supporting Emilia's quest for the throne, he was actually using her, Subaru, and Ram for his own goals, which involved killing the Divine Dragon and resurrecting his mentor. However, in Arc 4, he made a bet with Subaru and subsequently lost, forcing him to truly support Emilia, though he hasn't given up on his ambitions.
Roswaal is a rather tall man standing at 186 cm, making him taller than Natsuki Subaru by at least half a head. His well-toned body is slender and appeared delicate despite its impressive musculature. His very handsome face is ghastly pale which gives him the impression of a classic pretty boy. However, his physical beauty is somewhat concealed by his peculiar makeup and getup. Like previous generations, Roswaal had the same heterochromic eyes in the same arrangement. His straight indigo hair is long enough to cover his whole back and is usually tucked behind his ear on the left side of his head. His face is usually decorated with a light-lavender powder, purple lipstick, and purple eye shadow that is adorned on his right eyelid. His yellow left eye is also bedecked with eye shadow that is more elaborate than the right's eye shadow and covers the whole area around the eye rather than just the eyelid and accompanies his unusual outfit comparable to those similar to a clown or jester, consisting of a black hat, a top and bottom with different shades of purple, along with red and black boots and a cape. He also has a chain surrounding his right ankle.
Although rarely, Roswaal sometimes does make an appearance without his signature make-up. His skin complexion is noted to be very ghastly and pale and his eyes give off a gentle and rather welcoming expression, a polar opposite of what they give off when he's wearing make-up. When the situation calls for it, Roswaal also dons a more formal outfit, consisting of a long black coat that covers his entire body.
His original body, then-known as Roswaal Mathers and later referred to as Roswaal A Mathers, was male. His long straight indigo hair flowed freely down his back and both his eyes were blue. At the age of sixteen, Roswaal had a wicked charm about him that was only possible for a blooming young man of his age. He was also rather tall, towering over Ryuzu Meyer by a full head despite still having room to grow. Despite his youth, Roswaal possessed a natural elegance befitting of his lineage as a noble. He could usually be seen wearing rather well-suited black robes. Many of his physical traits, such as his hairstyle and colour, would be adopted by the descendants he possessed.
Roswaal comes across as an eccentric due to his flamboyant appearance and odd speaking style, the latter which he shares with his grandmother. However, he harbors a more calculating and reserved side with a sharp political mind and gaze that reads others quite well.
Roswaal cares about Ram and Rem a great deal and holds them in high regard among his staff. However, he is unusual among the nobility for having such close relations with Demi-humans to the point that many are hired by him. This has led to unsavoury rumours that have suggested he has a fetish for them. That said, Garfiel speculates this is actually because he's been gathering halves to the Sanctuary.
In actuality, his body is possessed by his ancestor, Roswaal A Mathers, whose purpose is to meet his teacher Echidna again at any cost, even if that means sacrificing himself or those close to him, making Echidna describe him as being "a little too earnest." He has figured out that Subaru is looping through some method, causing him to challenge him, and subsequently lose. Though he has agreed to help him after losing, he has threatened to force him to loop if he makes a mistake.
In the past, Roswaal was bright and a little prideful, until his encounter with Hector, the Warlock of Melancholy. His psyche was greatly wounded, and he started mimicking Hector's mannerisms including his eccentric way of speaking and his clown makeup. He has stated to Beatrice that on the inside, he is a clown, even without his makeup.
After the events of Arc 4 and after losing his cherished Book of Wisdom and the bet he made with Subaru, Roswaal cast a Curse Seal on himself, which acted as a safety mechanism, making sure he couldn't just randomly decide to go against the bet he had lost. If he does so, his body and soul will be destroyed, permanently killing him. However, as his Book of Wisdom has been destroyed, Roswaal decided to follow Subaru's path, which will eventually allow him to accomplish his four centuries old goals. Accordingly, he stated he'll make sure that Subaru will uphold his part of the promise as well–in case one of the people he loves will die, Roswaal will burn everything and everyone dear to Subaru, forcing him to restart.
Roswaal A Mathers, was born into the Mathers family, a noble house active within the Dragon Kingdom of Lugnica. The wealthy family owned, governed, and occupied large portions of populated land in the north-east region of the nation. The era in which Roswaal was born into had a distinct ignorance regarding magic, which was unfortunate for Mathers who possessed incredible latent magical talent. In his youth, Roswaal became known for his magical potency, although he struggled to comprehend the power within him. At a certain point he began suffering inexplicable burning sensations that would last for hours or even days and could not be explained by any doctor. As he tended to thrash and moan during these random moments of pain, no one ever dared comfort the boy. In fact, his family considered him a burden because of his unexplainable condition. As time went on, Mathers became more accustomed to the pain to the point that he could behave normally whilst under the burning sensation.
One day, when Roswaal felt that the pain was on its way, Roswaal rushed to his room to have some privacy. However, upon entry he discovered a beautiful white-haired woman sitting on his bed in black clothes. The woman stood up and approached Roswaal as she praised him for his capability to resist his pain. Just then, a jab of pain struck Roswaal, causing him to vomit onto himself and the woman. Feeling shame at what he had done, Roswaal tried to apologize to the woman. However she approached him before he could utter his words and kissed him on the lips. After holding the kiss for a few seconds, the woman backed away and explained that she had extracted the magical energy in his body, as the excess energy within his body was poisoning him. From the woman, Roswaal learned that mages with high quantities of magical energy in their bodies were susceptible to great pains and even death if they didn't get rid of the excess magic their bodies absorbed. The way to do this was to either use magic on a regular basis or release a large quantity of magic at once.
The woman explained she knew this because she had suffered similar problems in her childhood. After breaking into tears because someone finally understood him, Roswaal asked the woman her name. She introduced herself as an "evil Witch" whose name was the Witch of Greed Echidna. Roswaal introduced himself to her in turn, and eventually went on to become her loyal apprentice. He fell deeply in love with the Witch to the point that she mattered to him more so than anyone else including himself.
Throughout the years, Roswaal slowly began to unravel his magical talent and honed his abilities to near perfection although he was never able to achieve the same magical prowess as his mentor Echidna. By the time he was sixteen, Roswaal was already considered to be one of the top mages in the kingdom. Soon after, the Warlock of Melancholy successfully located Echidna in her Cloning Facility located in the Kremaldy Forest. Roswaal confronted Hector in order to buy Echidna some time but he ended up swiftly defeated and almost killed. In the last second, Echidna came to the rescue, fending off Hector and saving Roswaal's life. But the defeat Roswaal suffered was demoralizing and he was never able to fully heal himself again. Instead of achieving the pinnacle of Arcane Arts, he spiralled down the dark path of sinister magic, and over time, his mind had utterly changed. After Echidna died, Roswaal started to possess his descendants, with the purpose of bringing her back. Shortly after his thirtieth birthday, Roswaal A Mathers died and possessed the body of his son, Roswaal B Mathers.
Roughly 15 years before the events of the main story, His Majesty Randohal Lugnica held a ceremony in honour of then-14 year old Roswaal L Mathers inheriting his father–Roswaal K Mathers'–name, after the latter met a premature end. On his way back from the Royal Palace, Roswaal was robbed by a small kid. After successfully cornering the kid in a dark alleyway and demanding the return of his stolen golden-feathered ornament, Roswaal was interrupted by a large man who introduced himself as the kid's boss. Not wanting to shed blood, Roswaal moved in for a one-hit knockout, however, due to recently switching bodies and not yet being fully accustomed to the new body, the so-called boss took the hit and retaliated with his own, knocking Roswaal out instead.
Upon waking up, Roswaal quickly noticed a man standing next to him. He introduced himself as Russell Fellow and explains that Roswaal was likely mugged by The Brotherhood–an organisation running rampart in the Capital, stealing from the rich and demanding rights and equality for the poor. After teaming up with Russell and starting their search for the stolen ornament, Roswaal and Russell soon stumble across a 5 year old boy who urged them not to continue down the street as his father is currently working. Sensing the boy's peculiarity and noticing something's off, the pair complied to the boy's request, asking the boy who his father is, to which, the child states it's Heinkel Astrea.
After Heinkel's business with Marcos (Heinkel's "work" was trying to convince Marcos Gildark to re-join the Royal Army), Roswaal interjects, starting a banter with Marcos, which quickly turns into a fist fight. After both giving their all, Marcos finally surrenders and admits defeat, to which Roswaal doesn't take too happily, demanding the continuation of their fight as he could not accept his given victory. It is only after Russell interjects, that Roswaal dropped the lust for battle. After further debate, Marcos calls the young boy who robbed Roswaal a couple of hours ago, demanding him to return the stolen badge and apologize, to which, the boy–Bell–reluctantly complies. Roswaal, Russell and Marcos then discuss Marcos' involvement with The Brotherhood, asking him why he abandoned the Royal Knights. It is only after Marcos states that he's repulsed by the class-discrimination, that Roswaal smirks and requests Marcos to be his accomplice.
Not long after, Roswaal arranged a meeting between 5 highest-ranking members of both the Brotherhood and The Golden Wing, urging the two factions to form an alliance under Roswaal's supervision, as he, too, wants to make a change in the Kingdom, just like the two factions. After a bit of discussing things through, they agree and form an alliance.
Divine Protection (加護 Kago): Roswaal has the Divine Protection of Sorcery (魔導の加護 Madō no Kago), which makes him compatible with all six magic elements, enabling him to use the magic perfectly. Using this Divine Protection, Roswaal is considered to be the best in the kingdom in terms of mana usage, power, and speed, and is recognized to be as strong as one army. This Divine Protection was removed from the Light Novel, however Roswaal still retains the power described.
Magic (魔導士 Madōshi): Roswaal A Mathers is a mage capable of using magic of all six elements, whose skill had reached the pinnacle of human possibility, surpassing even that of his mentor the Witch of Greed. There is no magic that he cannot use or has difficulties acquiring, apart from Healing Magic, which he can't use as, according to himself, he lacks the necessary care for life. The original Roswaal, Roswaal A Mathers, was known as the most talented mage of his era, basically mastering all six forms of magic, though still falling behind Echidna in terms of overall magical knowledge and Beatrice in terms of Yin Magic knowledge. His twelfth body, Roswaal L Mathers, had magical potency that eclipsed the already impressive might of the original Roswaal. It has been stated that with the considerable magical power at Roswaal's disposal, he could single-handedly defeat a whole army's worth of soldiers. He was one of the rare individuals capable of channelling the magical power of all six magical elements—earth, fire, yang, yin, water, and wind. His skill was so impressive that he earned the titles The "Yellow" The "Green" and The "Red" that were bestowed upon the one considered the most skilful at utilizing earth, wind, and fire magic respectively. Roswaal's magical knowledge is, in fact, so advanced, that he's able to cast six different spells at the same time. It was noted that the technique of conjuring three or more spells at the same time is something that verges on the realm of gods.
- Flying Magic (飛行魔法): By combining the magical power of the earth, fire, and wind elements, Roswaal could float in the air, or, if he wished to do so, fly. He can reach speeds over 100km/h which is faster than a ground dragon and roughly on par with a winged dragon.
- Fire Magic: Fire magic was based around the manipulation of temperature rather than the manipulation of actual fire. By superheating the air around him, Roswaal could generate and manipulate powerful flames. There were several levels of fire magic that determined the amount and intensity of flames conjured. One of the most basic-level fire element spells was "Goa", which when cast, would produce a flame from Roswaal's hand that would incinerate its target. He could also use a higher version of Goa which produced a barrage of flaming bolts that could blanket an entire area with their destructive might.
- Goa (ゴーア): Roswaal manifests a blaze of fire, which incinerates a foe.
- Ul Goa (ウル・ゴーア): Roswaal fires a large number of powerful fire bullets. A powerful flame scatters when the bullets land.
- Al Goa (アル・ゴーア): Roswaal lets loose a massive inferno. Al Goa is mentioned to be one of his most skilled spells, falling behind only his threefold, fivefold and his trump card–sixfold magic spells.
- Weather Changing Magic: Roswaal is capable of casting weather changing magic. To be more specific, Roswaal could alter the state of the weather within a large radius, manipulating the temperature, moisture, and various other factors. Doing so created a large pulse of magical energy. As the spell is extremely advanced and needs a lot of mana to be casted, Roswaal has to arrange preparations before casting it, as well as using a catalyst in form of a mana crystal, to even be able to cast it in the first place. During Arc 4, he casted this magic to attract the Oousagi, as the snow is made out of mana and the Great Demon Beast is attracted to it.
- Rewriting Magic: By simply touching an incoming magic attack with any part of his body, Roswaal could easily rewrite the spell's composition, completely disassembling the incoming attack and absorb the mana through his own gate. He does so by using his own gate to interfere with the magic cast by an opponent, without coming into contact with their own gate. This skill is mentioned to be extremely hard to pull of and completely unheard of to use, during an ongoing battle, as it would require the user to have next to no regard for their own life–a small mistake would most certainly result in the caster's death.
- Threefold Magic: A god-like spell that has Roswaal conjure up 3 fireballs of differing hues, red, blue, and green. They can attack simultaneously in different directions and transform into towering flaming pillars or rolling waves of fire while expanding their size and hardness. The spell can break through other magics and are difficult to neutralize. This spell alone is far beyond a vast majority of mages' hopes of ever Successfully casting. In order to cast it, Roswaal had to use his mouth and both hands to activate the spells. He could also rewrite the composition of incoming magic attacks, disassemble it into mana and absorb it, allowing him to cast fourfold magic, which is roughly the same as threefold magic but has an additional spell.
- Fourfold Magic: Roswaal can cast fourfold magic, which allows him to summon four big and highly powerful fireballs which move at high speeds and follow the target until they eventually connect.
- Fivefold Magic: Roswaal can cast five different, extremely destructive spells at the same time. This attack allows him to scorch a target with intense fire, slice it apart with destructive wind blades and pulverise it, in seconds.
- Sixfold Magic: Sixfold magic is Roswaal's trump card and the very pinnacle of what he's capable of casting. The spell is so destructive that it allows him to compete with the Beast of the End itself. He has only been noted using it once–during his initial fight with Puck, one year before the start of the main story.
- Four Colours of Mana: In the second arc, when Roswaal was preparing to fight Beatrice, he conjured four mana orbs of different colour. Tappei later stated the spell to be one of his original and extremely powerful attacks which he didn't bother naming.
- Various unnamed spells: Due to his insane magical talent and a wish to improve himself, Roswaal modified and created a lot of spells. Most of the spells he uses are at least heavily modified if not created by him from scratch. Despite that, he never bothers naming these new and/or modified spells.
- Soul Transference: It is a lost forbidden magic art that allows a person to move their spirit from one body to another by over-writing the soul of the target body with their own. By doing this over and over to extend their life indefinitely, the user can achieve what Beatrice termed as "subjective immortality". However it has one major restriction in that for it to work, the person whose soul is overwritten must be of blood-relation to the caster. The spell was originally created by Echidna to gain immortality, but she could not complete it before her demise. Instead, it was finished by Roswaal who had been using it to survive until the present era.
Superhuman Physical Characteristics:
Several generations of Roswaal were physically honed to act at a superhuman level. For instance, Roswaal J Mathers trained for twenty years to defeat the failed Ryuzu Meyer clone Sphinx whilst relying only on her physical might and martial skill. Similarly, Roswaal L Mathers also sharpened his body into a lethal killing machine in case his magical power ever failed him. However, Roswaal found relying on physical measures somewhat distasteful for someone such as himself who was truly a mage at heart, however, he wouldn't hesitate to use it, if it meant giving his opponents a fair fight.
- Superhuman Strength: Roswaal L. Mathers also displayed a degree of superhuman strength, as he was able to impale the incredibly durable Garfiel Tinsel with his fist.
Martial Arts: Roswaal is able to fight physically, using moves such as throwing techniques against opponents. He is still vastly weaker than some unarmed fighters like Garfiel, but he's non the less capable of holding his ground against very powerful opponents, as seen when Roswaal J Mathers defeated Sphinx using her martial arts since she was unable to use magic. During Arc 4, Roswaal was capable of piercing through both Ram and Garfiel's chests with his barehand, heavily injuring both of them. His kick was capable of crushing Garfiel's head. He has also shown to be able to easily destroy a multitude of giant ice spikes sent hurling towards him at breakneck speeds.
- A Shockwave Strike: Long ago, Roswaal learned a highly powerful attack from a ninja from the west. With this attack, Roswaal can deliver powerful hits even if a hard object stands between his opened palm and his target. He does so by hitting his enemies with a shock wave, rather than with actual physical force. The strike is strong enough to break bones and rupture internal organs.
- A Shockwave Strike imbued with fire magic: During his fight with Marcos Gildark, roughly 15 years before the events of the main story, Roswaal used a Shockwave Strike imbued with fire. According to him, the strike would allow him to deliver a devastating strike capable of shattering bones and, due to it being imbued with fire magic, scorching his opponents' internal organs. If performed correctly, this technique is extremely deadly and only a few people would manage to survive it, let alone counter it.
Yellow Eye: Roswaal is able to use his yellow eye to break magic apart. This was first seen when Roswaal J Mathers fought against Sphinx and destroyed her Magic Circles with her Yellow Eye.
Extensive Arcane Knowledge: Roswaal's knowledge on magical practices was quite probably unrivalled, save for possibly his former master Echidna. Over his four-hundred years of life, Roswaal learnt numerous magical techniques and concepts from across all Four Great Nations, giving him a humungous stockpile of knowledge. He also spent time to read every single book inside the Forbidden Library that contained all of the important knowledge his master had accumulated during her life. Presumably, Roswaal knew of many spells and magical rituals forgotten by civilization due to the passage of time. In addition to harbouring an impressive understanding of pre-existing magical information, Roswaal was a keen inventor of new magical practices that were often known only to him. One creation of his was a magical theorem that allowed a mage to imbue objects with light magic enhancements. A majority of the magical spells Roswaal made active usage of were invented by or heavily modified by him. However, as he saw no point in it, Roswaal never allocated names to his techniques.
- Book of Wisdom (叡智の書): Just like Beatrice, Roswaal was given one of the two complete copies of the Book of Wisdom Echidna created before her ultimate demise. It allows Roswaal to use a limited version of the original Book of Wisdom, as it shows him a detailed path to his desired future. For four centuries, Roswaal strictly acted upon the Book's writ, doing exactly as it was written. The Book was destroyed by Ram at the end of Arc 4. The ashes were later collected by Otto Suwen, in an attempt to repair the book and hopefully read about Roswaal's plans. Unbenounced to Otto, however, his actions would prompt the Witch Cult into action, in the very next story arc.
- Roswaal's Black Gloves (ロズワールの黒手袋): The gloves are a special piece of equipment supposedly left behind by Roswaal's ancestors. They are said to be able to stop the cutting edge of a holy sword.
- Starting with his original body, Roswaal has been changing his middle initial every time he possesses a new descendant. His original initial was A, making his current body his 12th one.
- The initial "a" in Roswaal A Mathers' name stands for Altair.
- According to the author, Roswaal's birthday is September 16.
- All Roswaals' middle names follow the English alphabet thematically.
- Roswaal L Mathers has no sense of taste, there are only 2 foods he actually enjoys
- He has a habit of putting the crest of his family, a Hawk, into possessions and in clothes of people who live with him. It can be seen clearly in the sleeves of Emilia's outfit and in the cape of Subaru's knight outfit.
- According to Puck, Roswaal's power is on par with the Four Great Spirits.
- In the novelization of Arc 4, Roswaal is crueler than in the Web Novel, according to Tappei.
- Roswaal is said to be the strongest magic caster in Re:Zero. He also has one of the biggest mana supplies, most likely falling only behind Emilia.
- Roswaal L Mathers was in fact created with the intention to make a child with the greatest suitability for magic. Apart from Healing Magic, it was a success as he is the most powerful mage in Re:Zero.
- He read all the books in the Forbidden Library.
- His goal of killing the Divine Dragon is not necessarily connected with his goal to resurrect Echidna as the author stated that even if he crossed paths with his mentor, he would not give up on his quest of slaying the almighty Dragon.
- He's slated for an Arc 7 appearance where he's said to fully show how skilled he is in hand-to-hand combat.
- Wilhelm van Astrea is one of the few people Roswaal harbours genuine respect for their way of living and their convictions.
- According to Roswaal K Mathers, it's an unspoken agreement that after accepting the family name "Roswaal", the current head will not share their personal name with anyone.
- According to Tosca, Roswaal's mansion was identical to Echidna's, implying he modelled it after his teacher's.
- "It would be no idle boast to say you possess power on par with the Four Greats." Re:Zero Prequel: Bond of Ice Epilogue: The Meaning of Happiness: Section 2
- "It’s an unspoken agreement for us to hide our former names after we change them." Sword Demon Battle Ballad Act 11: Part 1
- "According to the 150-year-old Tosca, the Roswaal's mansion looks exactly like Echidna's mansion. In other words, Roswaal built his mansion on the model of Echidna's." Re:Zero Prequel: Loving the Days Gone By