You are All-Mights child, he never wanted you to be out in danger so he refuses to give you One For All

However in his battle with All For One at the Nomu Hanger All-Might was damaged more than he wanted to be meaning he can’t use his armoured version

Eventually he gave in, realising you weren’t any child anymore he lets you face All For One

You were Quirkless…however you and Malissa Shield Put your heads regather to make a super powerful suit that would replicate One For All as best as possible and it even has other cool tricks up its sleeve!

You stand in his way, your mission was simple…don’t let him reach Shigaraki and Deku

“They sent his Child to face me?”

He scoffs. Shigaraki’s rage getting to him meaning he wants All-Might to watch his own child’s guts spilled across the floor with them dead under his feet

“Fine then…”

He fires an Air canon at you Underestimating your power