Udûn

{t}: Add {b} or {r} to your mana pool.

{t}: Put a population counter on Udûn or remove three of them and create a 1/1 orc creature token.

{t}, sacrifice Udûn: search your library for The Black Gate and put it onto the battlefield.

"Sauron secured Mordor's defense sealing Udûn with the Black Gate ".