Bone Colossus

Trample, Reach
You may exile X skeletons you control to
reduce the mana cost of Bone Colossus by {b}
for each skeleton exiled. Bone Colossus enters
with 2X +1/+1 counters on it.
You may cast Bone Colossus from your graveyard by sacrificing 2 other creatures
and paying its mana cost.