User blog comment:IamJakuhoRaikoben/Chapter 390: The Story of a Boy, Review./@comment-110.20.169.85-20140627092840/@comment-5593752-20140627093737

Deliora was still alive because Iced Shell just trapped him and slowly drained his power until he was close to death.

Also I think Silver was visiting Ur's grave to swear vengeance or something. Or perhaps it was Gray's mother and some aspects of Silver's human personality occasionally win over Deliora.

And I reckon Silver probably had that type of magic in life.