The Great Ring of Power

{p/c}: Equipped creature gains shroud and shadow until end of turn. Put a -1/-1 counter on it.

{p/c}{p/c}: Attach The Great Ring of Power to target creature. Activate only as a sorcery.

At the beginning of the end step, if you control both Annatar, Lord of Gifts and The Great Ring of Power, you may exile them, then meld them into Sauron, the Deceiver.