Shadow, undisputable Negus

Negus (at the beginning of your unkeep, gain
control of all Demons you own. Each other
Demon you own gets +1/+1).
Flying, lifelink, first strike.
{b}{b}: Shadow, undisputable Negus gains shadow
until your next turn.
{b}{x}, pay X life: Shadow deals X damage to each creature you don't control.