Petelgeuse Romanee-Conti (ペテルギウス・ロマネコンティ) was a Sin Archbishop of the Witch Cult, representing Sloth. He debuted in Arc 3 as its primary antagonist and, though he met his end in the same arc, he was mentioned throughout the rest of the story.
In Arc 3, he led the Witch Cult to attack the Irlam Village and Roswaal's Mansion. Overall, throughout this arc, he acted as a foil to Subaru, but was ultimately defeated, getting his body crushed under a dragon carriage's wheels. During Emilia's trial in Arc 4, it is revealed that he was once very close to her and her aunt Fortuna, but went insane after accidentally killing the latter. He continues to be brought up in following arcs, primarily by the Emilia Camp and fellow Sin Archbishops.
Petelgeuse was a thin man, stood at 180 centimetres tall, slightly taller than Subaru. His cheeks were gaunt and the skin on his bones was unusually thin. If it weren't for the twinkle of madness in his grey eyes, the Archbishop would appear completely devoid of vitality. His complexion and lips, mirroring the rest of his figure, were deathly pale and had a sickly green-tint to them. Sloth's deep-green hair was fairly short but still long enough to catch someone's eye. Despite his madness and general lack of social decorum, Petelgeuse's hair was stylised neatly into a bowl cut. In the anime adaptation, Petelgeuse's eyes were black instead of grey. According to Subaru, Sloth's breath and body both smelled repugnant. He did have a strange and twisted sense of fashion as he could usually be seen sporting a pair of crimson-red teardrop-shaped earrings, similar to that of Regulus, with a small exception of Petelgeuse's being a tiny bit smaller and, of course, of different colour.
Out of the Sin Archbishops, Petelgeuse's outfit was the most similar to the standard dark-purple Witch Cult robe. He wore a clerical cassock that had a green stripe down the front and baggy sleeves with peach-coloured frills. Over the top of his cassock, Petelgeuse wore a purple cloak with an upturned collar, red seams, and pinkish interior. The cloak had a hood attached to it in the traditional Witch Cult style although Sloth was never seen wearing it. Lastly, a purple zucchetto with a grey ring around its edge rested atop his head.
About one hundred years ago, Petelgeuse could be seen as a much more normal member of society, sporting a rather tall and somewhat thin physique and sane and lively brown eyes. His hair bore perhaps a bit lighter shade of green, was much longer, and was evenly cut and tied to a small ponytail. His face wasn't as crazed and devoid of life, with his manner of speech being more calmed down and normal. He also did not self harm, meaning his fingers were not as disfigured as in the years prior to his demise. Emilia described him as very tall and skinny, but in a more lean way than frail.
It is also worth mentioning that due to his nature as a spirit and the ability to possess non-contracted spirit users, Petelgeuse often shifted between bodies. At some points, he even possessed women.
Petelgeuse was the general depiction of insanity, preferring to talk while in weird positions, such as tilting his head or bending his waist, and also liked to engage in self harming activities, such as crushing his own fingers, pulling his hair out, smashing his head onto nearby walls of the cave he was situated in, etc. Despite him being the Sin Archbishop of Sloth, he adhered to principles of living consisting of diligence and love. His love for Satella was the largest among the Sin Archbishops. He diligently followed and carried out orders from his gospel, always acting first in various situations, causing his name to be known as the most active Sin Archbishop, who was responsible for more than half of all the the Witch Cult's activities and attacks.
A hundred years earlier, Petelgeuse was a moderate, upright, and rational man. He was a close friend of Fortuna and Emilia, enough to be described as being like a family. He was also very respectful toward certain people, such as the elves of Elior Forest and the Sage Flugel. He was willing to sacrifice himself for the safety of Fortuna and Emilia, a trait which Pandora commended, and one which he would pass on to his future mad self. However, when Regulus and Pandora attacked their village, he accidentally killed Fortuna through Pandora's power, which combined with the damage he received when taking in the Witch Factors of Sloth, which he wasn't compatible with, causing him to go insane.
It is worth noting that both in his past and present, the members of the Witch Cult carried him in high regard, and carried out his orders diligently and without question.
Roughly 400 years ago, Petelgeuse helped in founding the Witch Cult for an unknown reason. The other co-founder is yet to be revealed. In the following centuries, Petelgeuse acted as the leader of the Moderate Faction of the Cult, carrying out different tasks. Even without having an Authority, he has been appointed the title of a Sin Archbishop, though he wasn't entrusted with Sloth until much later. Petelgeuse was acquainted with the Witch of Greed Echidna 400 years ago, and tutored her Artificial Spirit Beatrice manners. Although the nature of their relationship was unknown, it can be deduced that they were on friendly terms, as he had once joked to her that it was his duty to be disliked. At some point, he met Fortuna and befriended her, with Fortuna nicknaming him "Geuse." Through her, he learned of the Elves of Elior Forest, and the seal they guarded.
A bit over a century ago, Petelgeuse started to involve himself with the Elior Forest and its residents, periodically bringing them new clothes, accessories and sometimes even food from the outside of the forest. In the following months, he met Emilia who was, for an unknown reason, of great importance to him, causing him to break down in tears, due to happiness. This incident lead him to bond with both Emilia and her aunt Fortuna even more, however, the trio's happy times didn't last long. To his horror, Regulus Corneas and Pandora made their appearance in the forest, bringing with them the wrath of the Kurohebi as well as the Radical Faction of the Witch Cult who engaged in combat with the Moderate Faction. In dire need for a power strong enough to stop Greed and Vainglory and allow Fortuna and Emilia to escape, Petelgeuse resorted to his trump card; the Witch Factor of Sloth. Apologizing to Flugel, Petelgeuse took in the Witch Factor which immediately started ravaging through his body, making him suffer excruciating pain and crying tears of blood. As a side effect, however, he gained the Authority of Sloth which he named the Unseen Hands. This caused Pandora to grant him the seat of Sloth, which the turned down, expressing his disinterested in it. He then proceeded to fight Regulus, however, no matter how many times he pummeled the white haired Sin Archbishop, he wasn't able to overpower and defeat him. Soon, Regulus had enough of it and with a single wave of his hand, cut Petelgeuse's right arm off by the shoulder and well as decimating his legs by throwing dirt and gravel at him. Just as he was about to curb stomp his head, Pandora stopped him, causing Regulus to get unreasonably angry at her, killing her on sight. Upon using her Authority of Vainglory to erase her death from the past, Pandora removed Regulus' presence from the forest, reverting all the damage done by him which effectively healed Petelgeuse's near destroyed body. What followed was an intence battle between Pandora and a duo consisting of Petelgeuse and Fortuna. Their battle concluded in the very depths of the forest, next to the Seal Pandora wanted to open; with her Authority of Vainglory, she tricked Petelgeuse into thinking Fortuna was Padora, causing him to tear out her chest with his Unseen Hands. After realising what he had done, Petelgeuse's mind utterly shattered, plunging him into the depths of insanity and utter despair. After realising there was no way to convince Amelia to open the Seal, Pandora urged Petelgeuse to accompany her from the Elior Forest while Emilia slowly pushed the land into an everlasting permafrost.
In the following century, Petelgeuse had accepted the seat of Sloth, joining the Radical Faction of the Cult. He became notorious for his cruelty, frequently slaughtering entire towns and villages, acting strictly according to his Gospel's write. He was finally defeated by a combined force consisting of Natsuki Subaru, Julius Juukulius, Wilhelm van Astrea, Ferris and the Fangs of Iron, roughly a month after Subaru's arrival to the new world.
- Unseen Hand (見えざる手 Miezaru Te): The Authority of Sloth allowed Petelgeuse to utilize a power he called the "Unseen Hands". The Unseen Hands were a technique that allowed Petelgeuse to summon numerous invisible hand-like appendages from his body that he could move and extend telekinetically. An Unseen Hand was strong enough to tear through flesh, bend and break bones, and shatter rock. The Hands could be combined together to create larger and more powerful hands. If the Witch Factor he used to make people into his fingers with, returned to his body, he was able to summon up to one-hundred of them. At his maximum potential, the Unseen Hands and the force behind each one was akin to a cannonball. Save for Subaru, Petelgeuse was the only person who could see the Unseen Hands. Petelgeuse also displayed the ability to propel himself forward through the air using the Unseen Hands, making it appear as if he's flying, though in reality, he's simply playing catch with his body being the thrown object.
- Sloth (怠惰 Taida): Petelgeuse could let out a black wave toward his surroundings, corrupting the minds of those who have no knowledge of Spirit Magic. Those affected experienced hallucinations, auditory hallucinations, and severe pain, then exposed the whites of their eyes, foamed at the mouth, and were nearly driven mad. This ability was cut out of the Light Novel.
Magic User (魔法使い Maho Tsukai): Petelgeuse, prior to his absorption of the Sloth Witch Factor, was a practitioner of magic. Since his absorption of the Witch Factor of Sloth, Petelgeuse opted not to rely on magic in combat, instead using his Authority of Sloth. That being said, he still used it as a fall back for when his Authority failed him or when he was backed into a corner.
- Ul Dona (ウル・ドーナ): Petelgeuse's designated element was Earth, one of the four more common attributes, as he was a minor earth spirit. As such, he had the capability to use earth-based magic. One spell that the Archbishop of Sloth was capable of using was "Ul Dona," which, when used, would manipulate the earth around the caster to create a large protective dome, however, the walls could be blown apart by strong sources of magic, such as a fire crystal. Petelgeuse used Ul Dona to defend himself against Julius Juukulius during their battle to no avail.
Possession: While he differed from the norm as a Spirit, Petelgeuse could possess others' bodies, with Subaru describing it as a forcible one-way contract. Compatibility varied between people, which depended on whether the person had an affinity for Spirits, as he mentioned that Subaru's body was optimal while Ferris and Wilhelm's bodies were incompatible for various reasons. However, he was unable to possess people with an affinity for Spirits who already had a contract with one. He was usually accompanied by special followers, called the Ten Fingers, who acted as sub-commanders and spare bodies for Petelgeuse, with each one leading a group of several lower-ranking cultists. The fingers themselves had positions that corresponded with the names of fingers on the human body. To make other people into his fingers, he added Witch Factors to their body that allowed him to possess them, as he could possess people with an affinity for Spirits, but needed to make normal people into his fingers first. The author mentioned that Petelgeuse was unable to possess a Spirit Arts User who already had a contract with another spirit. He used this over and over to live for 402 years until he was killed at the end of Arc 3.
- Witch Cult's Gospel (魔女教徒の福音): As a member of the Witch Cult, Petelgeuse was the owner of a copy of the Witch Cult Gospel. Each Witch Cult Gospel was a replica of the Book of Wisdom, a book that had been in the possession of the Witch of Greed Echidna. The Book of Wisdom would provide exact details of future events concerning the Witch of Greed, essentially bestowing Echidna with a form of precognition. Unlike the original Book of Wisdom, the Gospels of the Witch Cult were imperfect replicas, meaning that, although they detailed the future of its owner, the events conveyed were subject to change and the information provided was often up for interpretation. The Gospels took the form of small black books that could only be read by their owners.
- According to the author, the basis of his actions, his relations with the witches, his past 400 years ago, and why his name is intentionally spelled as Petelgeuse are important plot points scheduled to be revealed in a future arc.
- Red Star is the common Japanese nickname for Betelgeuse.
- In Arc 5, Subaru noted that Betelgeuse, the star, was actually called "the hand of Orion", as it was located on the constellation Orion. This could possibly be a reference to his Unseen Hand.
- Petelguese's last name is named after a famous wine under the same name that was originated in the French Revolution.
- The author asked his readers on "Let's become a Novelist" about whether he should change the surname Romanee-Conti to something else in the Light Novel version. However, most readers told him to keep it as is, thus his surname was not changed.
- According to the author Petelgeuse was the "nicest" Sin Archbishop compared to the others, but after he went mad, he lost every ounce of dignity and morals, frequently going on rampages all across the world, becoming responsible for more than half of all attacks orchestrated by the Witch Cult, being known as the most active Sin Archbishop of the aforementioned cult.
- The author has stated that Petelgeuse used to be a lesser Earth Spirit
- The author mentioned that Petelgeuse was unable to possess a Spirit Arts User who already had a contract with another spirit.
- Before he lost his mind, Petelgeuse was shown to have a rather intimate and close relationship with Fortuna. Their relationship lasted for decades if not centuries.
- According to the author, there were times where Petelgeuse was forced to use a female body. Despite that, Fortuna still loved him.
- According to the author, the reason why Petelgeuse introduced himself as Geuse can be found by researching the star Betelgeuse.
- When the first season of the anime ended, Petelgeuse was regarded as one of the most memorable characters in the show.
- Petelgeuse shares several similarities with the character Caster from Fate/Zero which have been noticed, from his insane ax crazy behavior, to his usage of Dark magic that take the form of shadowy hands, to having an intense obsession with a female character from the past (Caster with Jeanne D'Arc and Petelgeuse with Satella).
- Petelgeuse shares several similarities with the character Joker from DC Comics. Both Petelgeuse and Joker have green hair, pale skin, and predominately purple clothing. They are both psychotic with little regard for the lives of anyone other than themselves and exude eccentric behavior such as laughing while committing morally sickening acts. Furthermore, both Petelgeuse and the Joker have stoked a personal rivalry with the protagonists of their respective franchises (Natsuki Subaru for Petelgeuse and Batman for the Joker). Lastly, both villains are presented as having horrific backstories that thrusted them into the comfort of madness and down the path of villainy against their own wishes.
- Petelgeuse and Fortuna's Japanese voice actors also voice Yuuki Asuna and Kirigaya Kazuto , a well known and popular couple from the anime series Sword Art Online, respectively.