So lets say Izuku gives up heroism but keeps up on hero news and such so he discovers Stain. He sees Stain as more of a violent vigilante and follows his career back to his vigilantism.
He becomes a huge fanboy and starts trying to immitate him and training. He gets into UA generals since hes not pushing to be a hero and doesnt have OFA. He does pretty well by the sports festival and is considered for transfer.
Hes trying to track down Stain after the sports festival and finds him in Hosu except instead of defending Iida he just gushes at Stain whos stunned at seeing such an enthusiastic fan. I cant decide if theyd bond over their admiration of Allmight or if Stain would change his views at learning that All mights lying about his quirk, form, and is telling quirkless kids they cant be heros.
Stain gets caught saving Midoriya from a Nomu but no ones knows their involvement since Iida probably dies.
Izuku ends up being recruited by Giran along with the other Stain fans and becomes the UA traitor.