User blog comment:Miskos3/Fairy Tail Episode 234: Tartarus arc Prologue: The Nine Demon Gates, Review/@comment-4933386-20150523124945/@comment-7418318-20150523224141

That can't be it for sure.

Deliora was frozen for 10 years before it finally perished seven years before the current point of the story. And we know for a fact that Silver only joined the Nine Demon Gates after Deliora was frozen by Ur.

Besides I doubt that a mindless beast like Deliora was ever part of the Nine Demon Gates or even an Etherias.