Dol Guldur

Dol Guldur enters the battlefield tapped.
{t}: Add {b}, {r} or {g} to your mana pool.
{x}{b}{r}{g}, {t}, Sacrifice another land: Target creature gets +X/+X and gains menace until
end of turn.

Beyond the river the land rose again like a wall, dark and drear. The sun had no power to enlighten the shadow of that hight.