Valli's godly grandparent was famed for being so beloved that all the creatures of the world swore not to harm him, and Valli has inherited a portion of this blessing from him. Valli cannot be harmed by others, and reality tends to twist to accommodate this fact. Bullets will miss, no matter how well trained the marksman is. People slip if trying to punch him. This doesn't take away anyone's desire to kill him, but people will simply find him impossible to hurt, and if they persist too long, they'll often end up injured themselves.
When it comes to natural accidents, rather than people trying to harm him, Valli generally comes out amazingly. If he was in a car accident, he'd walk away with some light bruising. If he slipped down the stairs, he'd feel a bit sore but nothing worse. An explosion might knock him over, but all the shrapnel will miss him.
Valli's blessing is lightened in cases where he knows he's going to get hurt. If he knows someone is lifting a piercing gun to give him a piercing, his power won't interfere with it. There's a similar effect when it comes to things like surgery: As long as Valli knows it's going to happen, it's alright. In cases where he would be operated on without his consent, the doctors would have similar issues to someone trying to harm him.
