WARNING: The following article contains major spoilers for Thor: Ragnarok, in theaters now.
One of the greatest things about the Marvel Cinematic Universe is that it does truly move its characters forward with shocking twists and revelations that actually remain in place by the film’s conclusion. The Thor that we meet at the beginning of his first movie is worlds away a different character from the man he is at the end of Ragnarok. With the loss of his hammer, the loss of his eye and the destruction of Asgard, Thor’s status quo has well and truly been shaken up in a big way.
However, the film also does an excellent — and much more subtle — job of setting up big changes in Loki’s life. In fact, the changes are so big, they may have massive repercussions for future movies, including a possible starring role of his own.
When Thor first returns to Asgard to find his brother impersonating their father, he makes the point of saying that Loki has been doing this their entire lives -- Thor gives Loki a chance at redemption, Loki stabs him in the back. In the most recent instance, Thor thought his brother died on Svartleheim following their clash with Malekith and the Dark Elves, but was dismayed to discover that he had instead led to the events of their father’s death and the return of their sister Hela. Later, when they meet up again on Sakaar, Loki chooses to sit back and exploit the favor of The Grandmaster instead of helping his brother escape and return to save Asgard, even though that’s exactly what Thor would do given the opportunity.
Loki only ends up helping Thor, Hulk and Valkyrie escape Sakaar when he realizes they’ll leave him behind if he doesn’t, and even then he attempts to betray Thor at the last minute. However, for perhaps the first time in their relationship, Thor managed to outthink his brother and slipped one of the Sakaarian control disks onto Loki, immobilizing him. What Thor says next to his brother is perhaps the most important conversation in the film, if you’re considering Loki’s growth as a character. He points out that throughout their lives, Thor has matured and changed; he used to be brash, headstrong and reckless, whereas now he’s more level-headed and mature. Loki on the other hand, has always been Loki, and if he wants to survive, he, too, needs to change.