Sergei is a Shaman who acted as an ally to the British Men of Letters, when they were met with an unsolvable problem.
Sergei was said to be an expert in magic and often aided the British Men of Letters, when they were met with an unsolvable problem. He had been contacted by Arthur Ketch several times, even though he never met him in person. During The Apocalypse, he met Gabriel and helped him with a cloaking spell, obtaining some of Gabriel's grace as payment.
Castiel found Sergei through Arthur Ketch. As Castiel approached Sergei, he trapped him in holy fire. After learning that Castiel was alone, he released him. Sergei assured Castiel that his job is solving the unsolvable and gave him a spell and a vial of Gabriel's grace. As payment, he asked Castiel to tell Sam and Dean that they owe him one.
As Sergei's spell didn't work and made Jack's condition even worse, Castiel called him for help. The Shaman told Castiel it was just an experiment. Castiel threatened Sergei, that if Jack dies, he would find him. An unfazed Sergei responded with "you can try".
Powers and Abilities
Sergei is incredibly powerful, since even the British Men of Letters gave high respect to him and his reputation is said to be "stellar".
- Shamanism - As a shaman, Sergei can "realign the harmonics of the universe" and is skilled in art of magic. He is called a professional by the British Men of Letters who often sought him out. His talent was even recognized by the Archangel Gabriel, who used one of Sergei's cloaking spells to hide out from his siblings.
- Supernatural Knowledge - Sergei is an expert in mysticism, esoteric and divinity and possesses a vast knowledge, even that lacks to another high specialists, as brothers Winchester, Castiel or Rowena MacLeod. He knew a procedure to slow a nephilim process of decaying, something that not even hunters and witches did, and he also states the he's been crossing the world studying and observing the skills of myriad witches, seers, holy men and others.
- Spell Casting - He has extraordinary knowledge of spellcraft, like a recharging spell, cloaking spell, holy fire and it is implicit that he can hide himself from anything.
- Supernatural Concealment - He invented a spell that succeeded to hide Gabriel from his brothers. He also sounded completely sure that Castiel, a seraph, would be unable to find him.
- Healing - As a shaman he is first and foremost a healer.