Tony Stark: MCU. The little town (Starklandia) they've all landed themselves in is unofficially named after him and he might have been sorry once, but he isn't anymore. He's the guy you go to if you need anything built or fixed up. He's also snarky.
Clint Barton: 616 comics. You know this dude. Look out for him and his dog around town. He (co)owns one of the three businesses in town, COFFEE. Guess what they sell!
Loki Laufeyson: 616 comics. He's Loki! But less movies and more comics. And less evil and more.... ambivalent with a side of smug. Also sometimes a woman, because Loki's like that.
Sirius Black: Harry Potter! Sirius is youngish, fun loving and pretty easily excitable. He's wizardly.