I started out backwards. Off the top of my head, a list of traitors:
Gorlim
Maeglin
Gollum
Ulfang
Mim
Most of Feanor's sons
Saruman
Gollum and Mim can be eliminated straight away - the former is the answer to a different clue, and the latter is too short to contain two scrambled words.
Searching scrambled bits of a few of the above found me a couple of godforsaken geographical locations, obscure genera, random political movements, and a massage therapist. Great.
