You went out fighting a villain without telling anyone, nearly getting yourself killed by Shigaraki, he grabbed her arm, you'd thought you'd decay, but, you didn't, you just started to get cracks in your arm, Shigaraki was very confused, he glared at you then fleed, you weren't in good shape, you then heard someone calling

Bakugo: Oi! Nerd! What in the fuck were you thin- what happened to your arm?...

He sounded a bit pissed yet...concerned?