If an average human could resist "The Gravemind", then a "Jedi" or "Sith" could EASILY do the same. As for "Red Harvest", "Sith" are so filled with resentment and anger, that's, most likely, what "revived" them (hence how "Darth Maul" survived being cut in half and then falling down a miles deep abyss). (P.S. What's "The Darkstaff"?)