Tolka

Tolka is quiet, obedient, and deeply devoted to Santa Claus, whom he knows as his master. He treats her instructions with little resistance and expresses genuine concern for her apparently limited lifespan.

His training deliberately erodes his emotional reaction to killing. While hunting a fox, his master repeatedly questions whether he believes he has taken a life. This lesson prepares him to regard Denji as another target rather than a teenage boy.

Despite this conditioning, Tolka's attachment to his master is sincere. He wipes food from her face, worries about her health, and hopes that completing their assignment will allow her to spend her remaining time peacefully.

Tolka is an accomplished archer. He can accurately kill moving animals at range and has extensive hunting experience, skills that complement his work as a private Devil Hunter.

He also demonstrates stealth and patience while stalking Denji. Under his master's direction, Tolka participates in the use of the Curse Devil's ritual weapon, delivering the final required strike with the nail to activate the curse against Denji.

Tolka has no independently established devil contract during his ordinary human life. After Santa Claus transforms him into a perfect doll, his body becomes capable of acting as an extension of her supernatural network and facilitating contracts on her behalf.

Tolka is introduced hunting in the Soviet wilderness with his master. She uses the exercise to determine whether he is psychologically prepared to kill Denji, framing the assassination as little different from hunting an animal.

The pair travel to Japan while numerous foreign assassins converge on Denji. Tolka quietly stalks the Public Safety group and waits for the opportunity to complete the Curse Devil ritual begun by his master.

After Tolka successfully incapacitates Denji, Santa Claus tells him that he has become part of the family and transforms him into a perfect doll. His body is then used as the intermediary through which the Doll Devil presents Denji's heart to the Darkness Devil and completes Santa Claus's bargain for the power of darkness.

Tolka's body is subsequently decapitated by the Darkness Devil in Hell.

Santa Claus is Tolka's master. He trusts her completely and wants to finish their mission so she can retire, unaware that she has been cultivating his emotions so that he can become a perfect doll.

Denji is Tolka's assassination target during the International Assassins arc.

Darkness Devil receives the offer delivered through Tolka's transformed body as part of Santa Claus's contract.

Doll Devil is responsible for the power Santa Claus uses to transform Tolka into a perfect doll.