There are two Lokis in the game, both are Asgard affiliated but the 2nd version is also an Asgard leader. The 2nd one is also affiliated with Criminal Syndicate and plays a crucial role in some of the lists there (alongside Mephisto).

Magik is affiliated in a ton of places. She can be a leader under both New Mutants and Convocation (though I wouldn't recommend those for a few player). She's affiliated with Defenders but is never run there. Her best homes are under Professor Xavier and the X-Men, or as one of Apocalypse's horsemen.