Remove the tragedy, have all the good things he's done be simply pragmatic, subvert the care he had with everyone, has his intentions be to rebuild the world where he is a god, have him always wanted to resort to the rumbling first, and let him be responsible for most of Aurille's actions.

So basically Light Yagami

This is tough. I mean it's Eren we're talking about, so, maybe have him (if it's even possible) have actions so heinous that his tragedy is ultimately invalidated, make him grow to despise his friends, have him take that scene were he beat Armin in Niccolo's restaurant taken MUCH farther than it should've been, and when he's confronted by Hange in the blimp about Sasha's demise, have his laugh not be out of sadness, but out of genuine sadism, like a final "Good Riddance".