Stucky AU? Where SHIELD finds Bucky in cryo in an old Hydra base, he has his metal arm but the brain washing/memory wipes didn't happen because the scientists in charge of him were killed. So he sat there frozen until a few years before Steve when he's found, heartbroken and on a revenge mission to get every lingering hydra agent or base destroyed. They took his sweetheart from him. Then he gets a call "We found him, Sargeant Barbes."