Avengers: Endgame - 10 Secrets We Just Learned From The Writers At Comic-Con

In Infinity War, Thanos has a clear purpose, and one fixed goal. Collecting the Infinity Stones is all he cares about, and so, the film was built around this mission, almost making him the protagonist.

But once he's achieved that goal... what do you do with him? That was the question facing Markus and McFeely during the development of Endgame, and it proved quite tricky to answer.

You can't just write him out of the film entirely, because if the story is about the Avengers trying to undo his universe-obliterating snap, then he will absolutely want to stop them doing that, right? But if you literally just showed him beating the Avengers in the last movie, how do you tone down his power levels (or make the rematch more even), without it seeming like a cheap nerf?

The Thanos conundrum caused the writers headaches for weeks, but the problem was solved by Endgame executive producer Trinh Tran in one succinct sentence: "what if we just killed him?"

Once the team had that idea nailed down, Markus said that it helped solidify Thanos' entire story arc, because it signified that his one sole purpose had been truly, irreversibly, fulfilled: his death sealed his victory.