The Gates of Finis

The Gate of Finis enters the battlefield tapped.
{t}: Add {r} or {b}.
{w}{u}{r}{g}: If you both own and control Emerald,
Ruby, Sapphire, and Topaz Dragonstones, exile
them and transform The Gate of Finis into Omniscient Eye
Pass beyond the Gate of Finis, and never again
may you return to this world