User blog comment:PUNCHURPREGNANT/Gray and Silver Predictions/@comment-71.183.188.204-20140612135605

Silver is Gray from the future. He is undercover, trying to destroy the ultimate Face in the past because we know that there are way too many FACE to destroy, then it must be one that will destroy all of them. Fairy Tale lost the battle in his alternate future and he went back to the past to help fix the mistake that Gray (Silver) may have possibly has caused. He visited his parents grave in 353 and smells like Gray because he is Gray.

Theory 2

He is Gray's father and Deliora, his demon form. He left Gray with his sister Ur and later found out that she was destroyed/killed by Gray's mistake.