The "FenriX" project was originally founded by the KGB in nineteen fifty six and focused on locating individuals with the Lycanthropy disease, capturing and enhancing them, teaching them to control their condition (often through brainwashing and minor torture) and then using them to fight other supernatural beings. On average, only one or two candidates out of a hundred were able to successfully control their animal instinctsand overcome their basic urges to kill.
It seems that the Russians have used the essence of several powerful Demons to create a number of Super Soldiers who they intend to use as agents against other Demons and Vampires.
The method of combining the human and demon essence is crude and said to be incredibly painful, being more mystical than scientific and was the same for all of the participants except for the initial success of Sergei.
While the other nine specimens were fully combined with the powerful demons thereby giving them all of the beings power, Sergei was infused with several drops of blood from an Old One. Though this gave him a small percentage of the creatures power rather than infusing the subject with the entirety of the demons abilities, the boost he got was considerable. Far outstripping any of the other agents but removing his sanity, and from a man already considered a dangerous sociopath.
As a side-affect of having the Old Ones blood, Sergei ceased aging. Despite being in his twenties when operated on during the nineteen fifties he still retains his youthful appearance. When Yurik was brought to the Lokrovitel compound as a child in nineteen eighty nine, Sergei took an immediate dislike to the crying child and made it his business to torment the child as he grew up, administering particularily brutal beatings on each of the boys birthdays; instilling a fear that lasts to this day.
There are ten known FenriX agents that survived the gruesome process, listed here in descending order of power.