Spoilers for Avengers: Infinity War and Endgame.

When Thor showed up in Endgame overweight, drinking and playing video games, a lot of fans laughed and a lot were annoyed. The God of Thunder had become a punchline. I think there was a reason beyond the jokes: at full strength, Thor would have ended the movie too early.

Thor at the start of Infinity War#

Thor: Ragnarok established that Hela drew her power from Asgard, which is why Thor chose to let Asgard be destroyed to stop her. By the opening of Infinity War, Thor had lost almost everything: his home, his father, his hammer, his brother and half his people. Thanos, already holding the Power Stone, defeated him easily.

Stormbreaker changed everything#

Then Thor forged Stormbreaker. He arrived in Wakanda and turned the battle in seconds. Moments later he drove the axe into the chest of a Thanos holding all six Infinity Stones, and nearly killed him. Thanos survived only because Thor didn’t “go for the head.”

That’s the key point: a Thor with Stormbreaker could seriously hurt a fully powered Thanos anytime and anywhere.

The problem for Endgame#

Now picture Endgame’s final battle with that version of Thor. The Thanos who arrives is the 2014 version, without the stones, facing Captain Marvel, Iron Man and an army of returned heroes. A fit, confident Thor with the rest of them would have overpowered Thanos, and the war would have been over before it started.

So Thor’s strength had to be turned down, physically and mentally.

Marvel had done this before#

Thor wasn’t the only one. In Infinity War, Hulk refuses to come out for almost the entire film. In Endgame, Captain Marvel, arguably the strongest Avenger, spends most of the movie off-world. When a team has characters who can win a fight single-handedly, the story has to find reasons to keep them out of it.

Why it still works#

The writers didn’t just nerf Thor; they gave it a reason. Not going for the head haunted him, and five years of grief and guilt turned him into the Thor we saw. Even then, in the final battle he still went toe-to-toe with Thanos alongside Cap and Iron Man.

In the story, Thor was weakened by guilt. Behind the scenes, I think he was weakened by the plot. Endgame needed Thanos to be a real threat, and a Thor at full power would have made that impossible.

What do you think? Was Fat Thor a storytelling necessity, or a joke that went too far?