Overgrown Citadel

({t}: Add {b}, {r}, or {g}.)
Overgrown Citadel enters the battlefield tapped.
Pollute {1}: (If you would discard this card, you may
play it for its Pollute cost. If it should enter the battlefield this way, target creature gains Wither.)
The fortress long abandoned by man, had become the
home of the darkest forces of nature.