A faction of Exorcist whose early members split from the Iron Thorn Circle and Transcendent Congregation long ago, the Fellbinders are an organization, primarily composed of warriors of some shape or form whose entire shtick basically consist, as their name implies, of forcibly binding supernatural beings to themselves as a mean of obtaining power. The more painful and destructive the process, the better for them. If Mages get called thieves of power, then Fellbinders find the power, break its legs with a baseball bat and take it in their van to do shady things to it.
Fellbinders operate primarily in cells with something akin to a mentor-student chain. Mentors usually have multiple students at once due to the high chance of death and/or terminal corruption.
Think the Exorcist chapter in Warhammer 40k mixed with Devilman and the Warcraft Demon Hunters.