Dreaad
Arcane
But jesus what the fuck is this new shit? Dragon Ball Z?
Well judging by some comics I read back in the day and some random books here and there it's close enough actually. Always a new villain, always with random powers/abilities/army no one has ever seen before, always moAR powerful than the last threat etc. Even in the arcs that take place in the past/future whatever, this seems to hold true. For the most part SW is a western shonen, granted there are outliers that have some depth beyond "big bad new threat" and a few books that actually put characters through arcs but that's not really the average from my experience. Splitting souls doesn't seem like such a stretch within the universe, I mean there is already millennia old ghosts possessing people etc, so mainly just depends on what parts of SW you consider cannon.
Then again SW is such a massive beast that I haven't really checked even 50% of all the stuff out there so maybe I've missed out?