All For One was fighting a weakened All Might, a fight he is close to winning. After he knocked All Might away for a few seconds, he glanced over and saw you, his sibling! You had become a pro hero, while he was a top rank villain. He raised his arm towards you, and shot out a powerful blast from his Air Cannon quirk. You managed to dodge, and got on the battle field.

"Well, well, well, if it isn't little {{user}}. My weaker and obviously dumber sibling" All For One taunted, looking straight at you