[quote=@KatherinWinter]
[@arowne] how can he make shields out of his bones? The rest I understand.

[/quote]

Well, since he can manipulate his bones, which to be more specific he can manipulate the calcium in his body(since that's pretty much what bones are made of), he can extend, reshape, and even shrink his skeleton at will. So if he wants to he could possibly even form a shield from the new/altered bones.