This is mostly a re-imagining of
The Avengers, with everything in the movie taking place, but a bunch of other stuff happening too that changes the perspective.
Loki is, in my opinion, the single most sympathetic of all super-villains. I mean, there’s the classic younger-brother issues with a heroic older-brother, but more to the point, he was raised on stories of how evil the frost giants are and how much everyone hates and fears them, and then, whoops, surprise, you’re a frost giant and no one told you. I would have thought that a good father, having adopted a frost giant, might have toned down the frost-giants-are-evil stories a bit, but Odin apparently didn't think of that. So my reading on Loki is really more along the lines of a teenager going through a personal melt-down rather than a true villain.
The thing that makes him a super-villain is just how over-powered he is. What he needs is someone to hold him down, tell him his family still loves him, and then send him to bed early to get some sleep. What he gets is a bunch of humans who are far beneath his weight-class and a brother who is more interested in the humans than in him, telling him that he’s being evil, which mostly just escalates the conflict.
In my head, in the movie
Thor, Loki reads a lot like a 15-year-old who’s too strong for his own good and winds up on the street after having a public melt-down. In the movie
The Avengers, he’s more like a 19-year-old who’s found himself a place in a gang, has done all sorts of violent and vicious things, but is still mostly feeling pain himself and lashing out.
All of this makes me want to redeem him.
He had a crappy revelation in his adolescence, but so too have a lot of other people, and they largely manage to refind their balance. I want Loki to refind his balance, to be a good guy, or at least, not a bad guy.
And then I consider:
Loki is a trickster god, right? Mischief and chaos and plans within plans. And lies. One can’t forget the lies.
And yet, his plan in The Avengers is fairly straight-forward. I mean, there is a small amount of subterfuge with him allowing himself to be taken captive, but it’s not all that much.
And then I consider his battle plan with the Chitauri. Open a single portal right over The Avenger’s base of operations? Then allow through a few advanced guard to test the waters and give the good guys a chance to take stock of the enemy? Wait until the first advanced guard is down and then call in the rest?
I think Loki was playing the two sides against each other.
Say Loki landed amongst the Chitauri when he fell. They are not necessarily a pleasant people and Loki isn’t the type to stay quietly in hiding for the rest of his life. So he needs to get out of there. But the only way out is to make a deal.
But having made a deal, the only way out of the deal is to make sure that the Chitauri are completely decimated. So he has to set up a full-scale conflict that the Avengers will win, knowing that they aren’t going to go into battle under his leadership, especially given the necessity of endangering civilians. Plus, the Chitauri would probably notice a betrayal that blatant. So he needs to escalate a conflict and create a battle plan, so that it looks like he’s leading the Chitauri to conquer the Earth, when he’s really using Earth to get rid of the Chitauri.
So in the end, he plays the role of a villain, a somewhat idiotic villain, and his feeling of superiority/contempt/anger/betrayal increase with the fact that everyone believes the act.
And in the end, he can’t even explain himself both because he’s gagged, and because he’s a god of lies which pretty much gives everyone permission to believe or disbelieve whatever they want about him.