(: Add or to your mana pool.)
Hollow Fortress enters the battlefield tapped unless you sacrifice a monocolored permanent.
, Sacrifice a Swamp: Add to your mana pool.
, : Target creature gains vigilance until end of turn.
: Add 
or 
to your mana pool.), Sacrifice a Swamp: Add to your mana pool.
, : Target creature gains vigilance until end of turn.
