Roughly stripped and beaten for being into gruesome stuff (5)
I believe the answer is:
ghoul
'being into gruesome stuff' is the definition.
(a person with morbid interests)
I don't understand how the remainder of the clue works.
(Other definitions for ghoul that I've seen before include "Evil presence" , "shade" , "Morbid soul" , "Morbid voyeur" , "Gruesome fiend" .)