Who Kills Thanos? - Predicting Avengers: Infinity War's Climax

4. The Cosmic Powers/Celestials

Right now, the question of which hero or group of heroes would be powerful enough to defeat Thanos is a pertinent one precisely because it all looks so likely. But what if the powers who exist on an entirely different level - and who control the very balance of the universe - could lend a hand?

What if Thanos' plan to rebalance everything by killing half of existence fundamentally disrupts the universe to the extent that its caretakers feel they can no longer simply sit by and watch?

So far, there's not a great deal of evidence of huge cosmic powers in the MCU, but they definitely exist. We've already seen Dormammu in Doctor Strange and the Watchers in Guardians Of The Galaxy Vol 2, and both The Collector and The Grandmaster have appeared. So there's no reason to think the others like Eternity, The Living Tribunal, Master Order, and Lord Chao don't exist.

And it would be somewhat fitting for a surviving Celestial (or group of them) to appear to claim the Stones back after they were introduced as a big part of the Stones' backstory. Plus, they'd be the two groups of characters who would be powerful enough to deal with Thanos.