Thor: The Dark World (2013)
Loki is a broken man in the events of Thor: The Dark World. His quest to rule Midgard was clearly a failure, so he quietly settled in to serve his dungeon sentence. But being Loki, he couldn’t let his brother have the satisfaction of seeing him wallow in defeat, so he projected an illusion of a smug, defiant god pacing around his cell.
It took an attack from Malekith the Accursed for Loki to realize the gravity of what was happening in Asgard. For as much antipathy as Loki had towards his brother and as much resentment as he harbored towards his father, Loki truly loved Frigga, his mother. Upon learning her death, Loki is seen grieving and is in enough pain to agree to join Thor on his quest to retrieve the Aether (also known as the Reality Stone) and get some revenge along the way.
It’s right before embarking on their mission that one can gleam Loki’s inner workings. Everyone is convinced that he’s going to betray Thor. After all, Loki has a history and has earned no one’s trust. But for as ambitious as Loki truly is, his loyalty is to Asgard and, ultimately, to his family. He may be a narcissist, but he still has a deeply rooted love for the ones who raised him.
On top of that, seeing Loki mock Thor by making himself into images of his Midgard friends is a reminder that as malicious as he comes across, Loki is jealous at his core. He’s jealous of Thor’s Midgard friendships, the favor he gets from Odin, and his status as a hero. Loki wants to be just like Thor.
To that end, the fight on Svartalfheim reminds everyone how well Thor and Loki work together. Fully taking advantage of Loki’s reputation, the two brothers stage a betrayal, which allows Loki to trick Malekith into releasing the Aether from Jane Foster.
Loki is thought to be mortally wounded in the ensuing battle, but it wouldn’t be Loki if he didn’t have another trick up his sleeve. The movie ends with him disguised as Odin, ruling Asgard just like he always wanted.
Thor: Ragnarok (2017)
All good things must come to an end for Loki, as Thor does eventually return to Asgard at the start of 2017’s Thor: Ragnarok. Loki’s disguise ultimately falls apart, but he isn’t taken down in a defiant manner, but in more of an “Aw, shucks, I guess you got me” way.
Their relationship changes, though, after Odin passes away early in the movie. Suddenly, there is no more trying to earn the favor of his father. There is no more petty jealousy over Thor being the favorite. With both of their parents dead, Loki starts to realize that it’s just he and Thor who remain. Pretty soon, Loki begins to see that there’s no Asgard, either, because Hela shows up and seizes it with an iron fist.
With all of that in mind, Loki heads over to Sakaar to start fresh. He tries to curry favor with the planet’s ruler, the Grandmaster, by serving under him. With Asgard out of the question, it makes sense that Loki would try and work his way up to ruling a new planet. But he just can’t seem to escape his brother, as Thor winds up on Sakaar himself.
Loki is much less a threat in Ragnarok as he is comedy relief. He’s subdued frequently by Valkyrie, while any attempts to betray Thor comically backfire, as Thor has become all-too-familiar with his brother’s tactics by this point. After fighting alongside Thor again, it becomes clear that Loki isn’t about to abandon his loyalty to Asgard. Bringing the warriors of Sakaar along with him, Loki tries to fight Hela until it becomes clear that there’s simply no beating her without bringing Ragnarok to pass.
It’s ultimately up to Loki to set these events into motion. Loki must now set out to destroy the realm he has set out to rule for years. He recovers Surtur’s crown and resurrects the fire demon with the Eternal Flame. But before doing that, Loki recognizes a certain artifact and grabs it. It’s the Tesseract, which was being held in Asgard for safe-keeping.
As Surtur lays Asgard to ashes, it’s Thor and Loki, side-by-side. Because no matter how much they’ve fought over the years, no matter their different outlooks and goals, they’re still brothers. And in the end, they fight as brothers again.
So that raises the question again: Is it a good idea to bring Loki back to Earth? The Avengers are not going to welcome him with open arms. No matter how much they trust Thor, they are not going to accept Loki, who nearly destroyed their world.
Heading into Avengers: Infinity War it’s important to remember that Loki is in possession of the Space Stone again. On April 27, Loki is going to prove who his loyalty truly lies with: his brother or himself.