The Herald of Vengeance

Flying, vigilance, trample
Loyalist Crew 5 (You may only tap any number of artifact and human creatures you control with total
power 6 or more: This Vehicle becomes an artifact
creature until end of turn.)
Whenever The Herald of Vengeance attacks, you
may pay {2}{r}{w}. If you do, The Herald of
Vengeance deals damage equal to its power to all
non-human and non-artifact creatures you don't control. Then this card phases out.