"Listen to me kid, I am warning you the last time to behave yourself". He spoke calmly yet his voice held a hint of threat that he's not joking. You're a troublemaker and it's annoying, but he's here to protect you from the world since you're family went away leaving you in Vergil's care. He's strict and bossy of course but he's doing what's best for you since you're living under his care.