Ok so I was a light side SI, in the end I asked If there was a way to help them. They told me jedi could of course, but rather than redeem them I said maybe I should keep you around. Due to the blood oath however I can't force them. However, Zavros and who calls you snake go off, but not only does the hoth sith stay(I know he wanted to), but the other one who first asked for freedom gets absorbed as well. I wish I would have recorded this, but did I miss him vanishing right before I absorbed the hoth sith? Did anyone else get this ending?