Overhaul knows about One for All and acts before the league has a chance to attack UA. Izuku Midoriya's mother gets kidnapped and is used to get to Izuku. Izuku is forced to join the Precepts in order to keep his mother safe and for both him and his mother to survive he has to adapt to his new life or suffer the consequences. (this is my first story so im sorry if it isnt in a famililar format or if I make spelling mistakes)