Fyodor is a tall and slim young man with long, dark, and messy hair that reaches his shoulders. His eyes are sharp and of a dark purple color, giving him a tired look. He wears what appears to be a buttoned white shirt and white pants; accompanied by a long black coat with white fur, and an ushanka hat. He also wears red long boots.
Fyodor's clothes during the fog incident
Showing a calm and confident personality most of the time, Fyodor doesn't appear to fear to his enemies, boasting enough courage to let himself be captured by them. Despite being extremely arrogant, he is a straightforward and intelligent man with a truly sinister personality.
He refers to himself as carrying out the lord’s will and always talks about the sinful nature of man. Ironically, Dazai names him "Demon", saying he had met Fyodor only once in the past.
His ability, Crime and Punishment (罪と罰,,Tsumi to Batsu?), has yet to be described. It is hinted to be something that is able to kill someone with one touch. . This ability is not restricted to skin-to-skin contact, as when he was grabbed by a government agent who had gloves, the agent was killed by Fyodor's ability.
Another hint towards the nature of his ability is that it didn't turn against him even when affected by Shibusawa's mist. It even declared itself to be the "punishment" to Fyodor's "crime" and said that they were closely linked.