I am having his bones be hallow, because a 30 foot wing span is just ridiculously wide, he'd never be able to be inside. Though I think hallow bones wouldn't make that much of a difference, the logistics of winged humans are just ridiculously impossible. Like what about his legs, they'd just be massive dead weight while he's flying, they'd probably interfere with his aerodynamics. But that’s the joy of fantasy. "Its magic" is a valid argument.
