Second Chance (at happiness)
Tony knew better than to play with alien toys. He really did. But there was just something so tempting about other-worldly objects. It turned out that he wasn't the only Tony Stark that felt that way. One explosion later, there's a brand new Tony in town. But there's something not quite right about this Tony and how he reacts to the team, the way he flinches away from Bucky or shakes when Steve picks up the shield or won't turn his back to Clint and Natasha.
It turns out that not every Tony Stark is as lucky as Tony, but damned if Tony, Steve and Bucky aren't going to fix that.
(or, the one where canon MCU Tony gets thrown into a fanon world and gets ALL THE LOVE from the fanon version of the team)