Avengers: Endgame - How Every Main Character Will Be Totally Different

4. Thanos

Then

Throughout Infinity War, and indeed before it, Thanos was singularly focused on balancing the universe through genocide in order to save it from itself. He's a megalomaniac with a messiah complex who believed only he had it in him to do the difficult things the universe needs.

Now

As hinted by the end of Infinity War, Thanos is now at peace. That's a fairly fundamental change right there.

When we meet Thanos again, we'll see what it means to be a war time leader in peace time. How he'll cope with having apparently achieved his goal, despite the results not actually going the way he predicted, by the look of Earth.

Fundamentally, Thanos is going to have to go through a major change in psychology during the events of Endgame. It won't be enough to simply steal the Infinity Stones and stop him from snapping his fingers, because it won't change his compulsion to rebalance the universe. He will still be focused on a Decimation event.

What the Avengers will have to do is work on the niggling seed of regret he will have for the death of Gamora and rewire his brain to realise that he shouldn't wipe half of existence out in the first place.