General Grievous

Whenever a Warrior attacks, you may have its controller create a 1/1 white Warrior B1 Battle
Droid creature token that's tapped and attacking.
{w}{u}{b}{r}{g}: Untap all attacking creatures. They
gain trample, lifelink, and haste until end of turn.
After this phase, there is an additional combat
phase. Activate only during combat.