The sole survivor of the Sirius clan. His home, Dogsville was destroyed by vampires in search of the Arc of Sirius. He was saved by professor Willard, and cosidered him as his father ever since.

Prior to the vampire attack on Dogsville, he was living with his mother and his brother. During the attack, he lost his mother when a vampire broke into their house, forcing Yuliy to escape with his older brother, Mikhail. During the escape, they are attacked by vampires and Mikhail does everything he can to protect Yuliy. After they are separated Yuliy suffers an injury by another vampire, but he killed it after the beast blood took over. That is when Willard finds him.

He is a werewolf, but his werewolf abilities are not fully developed because of interbreeding between werewolves and humans. He still has exceptional agility and endurance, his smelling is also fully developed, so he can smell vampires.

He is using a Three-section staff as his main weapon, but he's also talented with other weapons, like swords.