Tamara totally deserves an unhappy ending, but I don’t think I can cheer if it happens in a way that sort of condones our villains using their powers out of anger and frustration. I want to see them continue to redeem themselves–if they must slip, then they do, but it should definitely be acknowledged as a slip and they should pay for it in some way. So maybe Greg would have flipped and helped them, but they kill Tamara, and so he destroys something that would have given them an advantage. Something like that–I want the bad acts to continue to bite the people who do them. It can be fun to cheer our main characters achieving victory and payback, but for me, I want to see their characters growing in some way.
“If I had a world of my own, everything would be nonsense. Nothing would be what it is, because everything would be what it isn't. And contrary wise, what is, it wouldn't be. And what it wouldn't be, it would. You see?” -- Lewis Carroll, Alice's Adventures in Wonderland & Through the Looking-Glass