User blog comment:LordLuminous/Silver being Deliora = Impossible? Theory/@comment-85.221.190.231-20140706080545/@comment-7418318-20140706082151

Just because he wasn't one of the Nine Demon Gates doesn't mean he couldn't have been a member of Tartaros. Lamy and Yakdorgia for example were Tartaros members without being Demon Gates too.

If Kyouka (since she seemed to be in command most of the time while Mard can't be bothered) thought him a potentialls valuable asset, she might have had him resurrected even though he was one of the lesser Demons until he powered up.