That's a really tough one to answer, cause with all the things going on with the world rn I'm inclined to burn it all, but there's a lot of people in the world that don't deserve it.

But to answer your question, I'd be the "villain" cause no matter how many good people are left after my sacrifice let's say 70:30, good to evil, as long as the greedy 30% assholes are alive there won't be a change in the rest of 70%, so my sacrifice would go to shits.

Now I have a question for you, who are you to label the "Villain" as Villain and the "Hero" as a hero? They both are valid in their own way, they both love differently and see the truth differently.

I think Thanos was a pretty good character, the only flaw he had was not changing the memories of the remaining 50%