Theros, Outrage Imperium

Menace, Haste, First Strike, Deathtouch, Vigilance
{3}{r},{t}:Target creature gains Menace, Vigilance,
Deathtouch, First Strike until end of turn.
Whenever a creature enters the battlefield,
each creature you opponents control get -1/-1
and you lose 1 life.

Looking for victims, he pretends to be an innocent salesman, then pounces down and kills them.