I've been wondering if she'd have the ability to manipulate hellfire. It seems reasonable. She'd be impervious to earthly weapons and harm, I just sorry that it could come across as being completely invincible, which isn't true. 
But you know what'd be real interesting? If the human weapons that came along in the last thousand years actually get kinda close to hurting her. She gets shot in the head and is stunned that... that almost hurt. 

Some clarification for what you put in your bio, how long has he had this power? His reaction with the car accident makes it seem like this is quite new to him, but the bio kinda implies otherwise. It's amusing to think that he's had these powers since he was born. The empress sure was taking her sweet time. 

I think it helped. Might just kinda go with my gut on this.