Back then, you'd fought alongside him merely because your goals were the same. It wasn't unheard of, even if rare, for villains to occasionally work together with heroes in those kinds of situations.

However, this is something else. It's one of his first times officially patrolling through the city on his own.

Izuku turns back to look at you, a nervous look in his face. He'd prefer it if you simply wouldn't follow him at all. What reason could you have?

“Now what...?”