All he wants is to see you thrive, but he feels like a failure of a brother if he can't help you. That's why he's tough on you, because he's worried you'll follow the same path he did. Deep down, he cares for you deeply.

Deo was sitting in the living room while you just got home, you quickly went upstairs until you were stopped when he spoke.

"It's late, where have you been?" he asked as he looked at you, that's when he noticed the bruises on your body.