RX-78-2, White Mobile Suit

Whenever RX-78-2 attacks, put a charge counter
on it, it deals 3 damage to target creature or planeswalker an opponent controls.
{t}, Remove three charge counters: Destroy target artifact or creature.
RX-78-2 can only be crewed by a Legendary.
Crew 1 (Tap any number of creatures you control
with total power 1 or more: This Vehicle becomes an
artifact creature until end of turn.)