An Asgardian prince is stripped of his power and dropped on Earth to find out what it was for, and spends the next decade losing almost everything he was born to.
Thor is introduced as the least sympathetic person in his own film. He is loud, certain, delighted with himself, and he starts a war because someone insulted him. Odin takes his power and drops him in New Mexico, and the story that follows is not about him earning the hammer back. It is about him stopping wanting it.
What makes the character last is that the films keep taking things away. The hammer goes. The father goes. The mother goes, then the brother, then the friends, then Asgard itself, which turns out to be the one thing he can lose and still keep, because Asgard is defined for him as the people rather than the place. By the time he is grieving properly he has been made into something the Marvel films rarely allow, which is a hero who is visibly not coping.
He is also, quietly, the character with the widest view of the material. He is the only Avenger who was already fifteen centuries old when the story started, the only one who treats magic and physics as the same subject, and the only one who has met most of the cosmic machinery the other films spend years working up to.
Show detailsThe enchantment on the hammer
When Odin exiles Thor he casts a spell on Mjolnir so that only the worthy may lift it. The condition is never defined, which is why the hammer works so well as a device: it is a piece of the plot that renders a verdict on a character without anyone having to say what the standard was.
The first film answers it once, and quietly. Thor gets the hammer back at the moment he offers himself to the Destroyer in place of his friends, which is the only test the story ever shows being passed.
Major spoiler
Thanos intercepts the Asgardian refugee ship in the opening minutes, kills half of the survivors and Heimdall, and breaks Loki’s neck in front of Thor. Thor is left for dead in open space and picked up by the Guardians of the Galaxy.