(: Add or to your mana pool.)
Tomb Vents enters the battlefield tapped unless you sacrifice an artifact.
, , Sacrifice Tomb Vents: Put a -1/-1 counter on target creature.
, : Draw a card, then discard a card.
: Add 
or 
to your mana pool.), , Sacrifice Tomb Vents: Put a -1/-1 counter on target creature.
, : Draw a card, then discard a card.
