User blog comment:IamJakuhoRaikoben/Chapter 390: The Story of a Boy, Review./@comment-4489126-20140627133949/@comment-7418318-20140627135839

So your saying out of the entire town's slaughtered population, Deliora just happened to take one of the two bodies that is connected with the person who would later become the pupil of Ul, just by coincidence? With his comment about "only eating Devil's souls" I doubt he would absorb something from every Human he killed.

I think it's more likely that Deliora has some regenerative abilities that managed to restore the half-decayed body into prime condition after possessing it (Deli did have seven years time to regenerate the body, thanks to the timeskip) or that Lamy was able to restore the body in Hell's Core before Deliora possessed it. From Ezel's and Franmalth's short appearance in Hell's Core before Mira busted it, we know that even without a body, they can still communicate with people near their tanks.

As for how badly the body was decayed, he was buried (I assume someone buried him) in a very cold place, so the decaying process would be slowed down... but it was still ten years between Silver's death and Deliora's release from Iced Shell. Must have been a rather unpretty sight.

Or maybe Keith was of some assistance. Since he's a necromancer, partially decayed corpses would be right up his alley.