Can I tell you I'm kinda obsessed with Loki?
There was a whole bunch of things I was thinking of while watching the two movies (no exception, of the Erik/Charles, one-sided Raven/Charles, or some odd mix of Erik/Charles/Raven kind...or even Thor/Loki -don't ask, I'm not sure where my mind comes up with all this). But the two main ideas I want to work on and look multi-chapter (the others I mentioned being that of the one-shot kind), are a Naruto and Harry PotterxThor cross.
God of Mischief is a Naruto fic, where Naruto is telepathic (like Charles dear!), but mixing up his personality like Loki's. I'm leaning toward making him a conqueror, eh. Hence, the mixing of X-Men and Thor, though.
The other is The Irony of Magic, where after Loki falls into the abyss created by the collapsing bridge at the end of the movie, he ends up on Earth...but found by Harry Potter, of all people. Still not sure when to set it for HP. It will eventually be a LokixHarry fic, though.
Updates on that, I'll follow up for you guys, but for now I'll get to writin'.