Mountaintop Fortress O' Doom

This land enters the battlefield tapped.
{t} add {b} or {r}
{t} add {b}{b}{r}{r}. spend this mana only to cast
red, black, or red/black spells.
{b}{b}{b}{r}{r}{r}{t}. target player loses X life, where
X is the amount of red, black, and red/black permanents you control. Use only as a sorcery