Heretics of Saint Scarif
From Warhammer 40k - Lexicanum
The Heretics of Saint Scarif were a Chaos Cult, active at some point prior to 241.M41.[1]
They were known for their method of ritual killing; they would cut off their victims' hands and, after ramming a quill into the stumps at the end of their arms, the Heretics would force their victims to write a final confession before they died.[1]