This is something I've been thinking about for a very long time, and I asked some people about it. I know that if I do this wrong I will definitely make readers mad, but would this ending anger you as it is right now? Someone hurts the MC and causes him a lot of pain, so he gets revenge on them in a rather subtle but serious way. Time goes on, and the MC ends up with a happy ending (for now). There will also be foreshadowing showing that something bad is going to happen by having someone else say he shouldn't have did what he did. This person also warned him against doing this in the first place. The bad thing he does ends up coming back to bite him, and he dies at the end, along with a completely innocent character. So, would this make you mad as a reader? EDIT: he does become famous after his death, which was a dream of his.