Roy Alphard (ロイ・アルファルド) is a Sin Archbishop of the Witch Cult, representing the bizarre eating aspect of Gluttony. First introduced in Arc 5, Roy later served as one of the main antagonists of Arc 6, alongside his brother and sister.
During the events of Arc 5, he ate Julius' name, causing everyone but Subaru to forget about him. In Arc 6, however, he made a big mistake when he tried to devour Reid Astrea, only to have his body taken over. While he regained control of his body after Reid's soul shattered due to it being incompatible with Roy's body, the fatal wound rendered him unconscious and he was sealed away with the usage of Yin Magic.
Roy has long, disheveled dark brown hair, along with emerald green eyes that are yellow in the center and have a poisonous glimmer to them. He also has a young look, a mischievous smile, and wears a piece of cloth around his body.
Unlike Lye, Roy doesn't care about what he eats, nor does he place any special emphasis on who he eats with like Louis. As bizarre eating, his approach towards his meals is much more casual, emphasizing quantity over quality as seen when he ate Julius despite admitting he had a bland taste. As described by his brother, he simply wants to eat without any thought or preparation put into it, for which he was repeatedly criticized by his siblings. He isn't as close to Louis as Lye is, but is nonetheless devoted and caring towards her. He speaks in a collective manner using us and we instead of first or third person.
In combat, Roy strives to exploit his opponents' weaknesses, unlike his brother who likes to give his opponents a chance to compete with him. He views combat as nothing more than a violent way of getting his meals.
Authority of Gluttony (暴食の権能 Bōshoku no Ken'nō): Roy is able to use the Authority of Gluttony.
- Gluttony (暴食 Bōshoku): Roy can eat the name and memories of their opponent. To eat a name, he touches them with his left hand, then licks the palm of the same hand. Things such as experience, talent, and the likes and dislikes of human relationships serve as food for him, allowing him to take advantage of any abilities or memories his opponents had. However, if Roy eats a fake name, he becomes plagued with severe nausea. Even after killing Roy, the names and memories of his victims will not return to their original owners.
- Those that have had their names eaten have their existences erased from the world, destroying any human relationships along with negating any contracts with Spirits.
- Those that have their memories eaten become amnesic and any characteristics they may have had are reset, effectively making them into a different person.
- Those that have both their name and memories eaten simply become a shell, and although they live, they no longer eat, excrete waste, or age, putting them in suspended animation.
- They cannot eat the same person twice until that individual gains enough new memories to establish a different sense of self from their old one.
- Eclipse (蝕): Eclipse is considered to be the trump card of gluttony. It is split into two types; Solar Eclipse (日食 Nisshoku) and Lunar Eclipse (月食 Gesshoku).
- Lunar Eclipse allows the holder to use the victims' memories and harvest their skills and knowledge. Roy used Lunar Eclipse to boost his physical strength and speed in his fight against Julius Juukulius and Ricardo Welkin. It is worth noting that by eating a person's name and using Lunar Eclipse, Roy does not gain his victims' Divine Protections, Spirit Arts or Authorities.
- Solar Eclipse, however, allows the holder to harvest his victims' name and transform their appearance accordingly. Louis, for example, transformed into Neiji Rockheart and numerous other victims she and her two brothers had eaten throughout the years using her sibling's body.
- Demon Beast Control: Because Lye, Roy and Louis possess the Witch Factors of Gluttony which were previously in Daphne's possession, they can direct Demon Beasts to attack certain areas. This is why the White Whale’s attacks were coordinated with those of the Witch Cult. In Arc 6, Lye and Roy are able to get to the Pleiades Watchtower in half a day by commanding the Demon Beasts in the Augria Sand Dunes, and order them to attack the Watchtower. Despite his ability to control the White Whale and the Great Rabbit, even if Roy had help from his older brother and younger Sister, they wouldn't be capable of controlling the Black Snake, according to the author.
Master Class Fighter: Through the accumulation of souls eaten, Roy gains any abilities his victims once had such as martial art techniques and magic. In turn, this has granted him extraordinary combat strength. He was able to overpower both Julius and Ricardo who are noted to be very strong.
- Snake of the Twin Sword: A sword technique that launches several combination slashes at high speed.
Equipment: Roy wields two claws from his hands that he uses with his speed and lightness. He also wields daggers that were hidden inside of his clothes.
- Witch Cult Gospel: As a member of the Witch Cult, Roy 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.
- Like the other Sin Archbishops (with the exception of Stride Vollachia), Roy received his namesake from a celestial body. Alphard is the name of the brightest star in the Hydra constellation. The star was also known as "the backbone of the Serpent" to the Arabs.
- The reason why he has the moniker "Bizarre-Eating" is that out of the three he has no standards when it comes to food.
- Roy, similarly to Lye Batenkaitos dislikes using Solar Eclipse. According to him and his brother, it seems to make him experience the victims' thoughts which make him feel like he's being damaged. He describes this feeling as unbearable.
- It is heavily hinted that Roy is working for Mother, being one of her "children", just like Elsa, Meili and Reisel.
- In a Q&A, the author stated that if Daphne and Lye Batenkaitos, Roy Alphard and Louis Arneb were to fight, it would most likely end in a draw.
- Roy was sealed off in the same way as Sirius and Satella; with the usage of Yin magic, rendering him stuck in time.