Barok, Suppressed by Chains

Flying, trample, defender.
Compromise (Your creatures can help cast this spell.
Each creature you sacrifice while casting this spell
pays for {1} or one mana of that creature's color.)
{3}{b}{b}: Sacrifice target creature you control.
Barok, Suppressed by Chains gets +X/+X where
X is that creature's converted mana cost, and
loses defender.