Swamp Citadel

{t}: Add {b} or {g} to your mana pool.
{t}: Add {b}{g} to you mana pool. Only activate
this ability if you control Fallen Citadel or
Frozen Citadel.
{t} Add {b}{b}{g}{g} to your mana pool. Only
activate this ability if you control Fallen Citadel
and Frozen Citadel.