Rok, the Flayer of Men

Firststrike, menace
When Rok enters the battlefield, destroy target creature. It can't be regenerated.
{1}{b}: Creatures your opponents control get -1/-1
until end of turn.
{1}{r}: Rok gains +2/+0 until end of turn.
{t}, {1}{r}{b}: Creatures you control gain +1/+1 and menace until end of turn.