Crush Bones

Cast before you declare your attack. Target
opponent creates X 1/1 black Skeleton tokens.
X is the amount of swamps they control +3.
Choose a Barbarian you control to attack that
player alone. Put two +1/+1 counters on that
Barbarian. All Skeletons must block if able.
Create two treasure tokens if Barbarian is not
destroyed.
If this card is in your graveyard, you may pay
{g} and shuffle it into your library.