When Rot Bastion enters the battlefield, sacrifice it unless you pay .
: Add or to your mana pool.
: Add to your mana pool. Put Rot Bastion on top of your library.
: Rot Bastion becomes a 2/2 black Rat creature until end of turn. It's still a land.
.
: Add or 
to your mana pool.: Add 
to your mana pool. Put Rot Bastion on top of your library.
: Rot Bastion becomes a 2/2 black Rat creature until end of turn. It's still a land.
