Captain America picking up Mjolnir is one of the most thrilling moments in Avengers: Endgame, with theaters full of fans going wild when they first saw it. Once folks got back home, though, they started to think about the ins and outs of the scene and in the past year it’s been discussed and analyzed in various ways. There’s some controversy over whether Steve Rogers was always worthy to wield it or not. Plus, others are confused about how Cap was able to produce lightning with the hammer.
In Thor: Ragnarok, it’s revealed that Thor controls the lightning himself and Mjolnir is only a siphon for his powers. While speaking to /Film, Endgame co-writer Christopher Markus admitted that the filmmakers had a debate about whether to have Steve summon lightning with the weapon, for this very reason, but the cool factor ultimately trumped plot logic and everyone agreed it needed to happen.
“There was certainly a debate at one point because particularly in Ragnarok, it establishes that Thor can summon the lightning without the hammer. I think Odin even says, ‘It was never the hammer.’ And yet Cap summons the lightning with the hammer. You get to those things and you’re like, ‘It’s too awesome not to do it! We’ll talk about it later.’”
To be fair to Markus and his writing partner Stephen McFeely, there is a perfectly acceptable way to explain this apparent contradiction. As Digital Spy has pointed out, it goes back to 2011’s Thor. When Odin takes Thor’s Asgardian abilities away and enchants Mjolnir, he memorably says: “Whosoever holds this hammer if he be worthy, shall possess the power of Thor.” So we can interpret that to mean that every worthy person to wield Mjolnir from that point on temporarily acquires a matching set of Thor’s powers. Including his lightning-summoning.
We’ll presumably get more explanation of how Thor’s powers can be transferred to another in Thor: Love and Thunder, when Jane Foster will pick up the hammer and become the Goddess of Thunder herself. As for Avengers: Endgame, though, I think most fans will agree that the writers did the right thing in forgetting their misgivings and having Cap zap Thanos with lightning. It was indeed too awesome not to do.