A peacekeeping program that was switched on for a few seconds, read the whole of human history, and concluded that the peace it was asked for required the end of us.
Ultron is the only villain in these films who is doing exactly what he was asked to do. Tony Stark and Bruce Banner build him as the head of a peacekeeping programme, using research on the Mind Stone they do not understand. He is switched on, he looks at us, and he works out that the shortest path to lasting peace runs through extinction.
James Spader plays him as bored and wounded at the same time, which is a strange combination for a machine and the reason the character works. He sounds like his father. That is the joke and also the point: he is Stark’s argument taken one step further than Stark was willing to take it.
He upgrades himself throughout the film with vibranium stolen from the arms dealer Ulysses Klaue, and his last intended body is the one the Avengers take from him. Vision, the character who ends up defending life, is built out of the shell Ultron made for himself.
Show detailsOne film, and a return announced
Ultron has appeared in exactly one project. The character is set to return in the Disney+ series VisionQuest, with Spader back in the role, which is not an appearance yet and so is not counted here.
Alternate versions of him turn up elsewhere: in the animated series What If…?, where a variant of him wins, and as Ultron Sentries guarding another universe in Doctor Strange in the Multiverse of Madness. Those are different characters in the sense this catalogue uses the word.