Petelgeuse Romanee-Conti (ペテルギウス・ロマネコンティ) was the primary antagonist of Arc 3. He was a Sin Archbishop of the Witch Cult, representing sloth. He was later killed by Natsuki Subaru with the help of Julius Juukulius.
Petelgeuse has short dark green hair that is cut neatly along with gray emotionless eyes. He wears a black, green, and red robe along with clerical attire. Perhaps one of his more subtle features are his two small red earrings that he's seen wearing.
A hundred years ago, his appearance was mostly the same, except that he had a tough yet gentle look. He had a sinewy and tall body, longer dark green hair and also wore a black clerical robe.
Petelgeuse prefers to talk while in weird positions, such as tilting his head or bending his waist and also likes to injure his own body. His principles of living consist of diligence and love, his reason for living to prove that. His love for Satella is the largest among the Sin Archbishops. He diligently follows orders, always acting first in various situations, causing his name to be well known.
A hundred years earlier, Petelgeuse was a moderate, upright and rational man. He was close friends with Fortuna and Emilia, enough to be described as being like a family. However, when Regulus and Pandora attacked their village, he accidentally killed Fortuna through Pandora's power, causing him to go mad.
Authority of Sloth (怠惰の権能 Taida no Ken'nō): Petelgeuse was able to use the Authority of Sloth until his Witch Factors were taken by Natsuki Subaru following his death.
- Sloth (怠惰 Taida)
- Petelgeuse can let out a black wave toward his surroundings, corrupting the minds of those who have no knowledge of Spirit Magic. Those affected experience hallucinations, auditory hallucinations, and severe pain, then expose the whites of their eyes, foam at the mouth, and are nearly driven mad. This ability was cut out of the Light Novel.
- Unseen Hand (見えざる手 Miezaru Te)
- Petelgeuse can cause physical interference by creating an invisible force field in the shape of a hand. The effect area, power, and number of hands are based on the user. Normally, Petelgeuse is only able to use seven hands however, if the Witch Factors he used to make people into his fingers returns to his body, he is able to summon up to a hundred or more of them. He can also combine hands together to increase their size.
Earth Magic: Petelgeuse was able to use Earth magic and was skilled in it.
- Ur Dona (ウル・ドーナ): Petelgeuse was able to lift thick walls of earth around himself in a shape of a dome.
Possession: While he differs from the norm as a Spirit, Petelgeuse can possess others' bodies, with Subaru describing it as a forcible one-way contract. Compatibility varies between people, which depends on whether the person has an affinity for Spirits, as he mentioned that Subaru's body was optimal while Ferris and Wilhelm's bodies were incompatible for various reasons. He is usually accompanied by special followers, called the Ten Fingers, who act as sub-commanders and spare bodies for Petelgeuse, with each one leading a group of several lower-ranking cultists. The fingers themselves have positions that correspond names of fingers on the human body. To make other people into his fingers, he adds Witch Factors to their body that allows him to possess them, as he can possess people with an affinity for Spirits but needs to make normal people into his fingers first. He used this over and over to live for 402 years until he was killed at the end of Arc 3.
- 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.
- Petelguese's last name is named after a famous wine under the same name that was originated in the French Revolution.