Miku of the Warrior's SEKAI

Whenever a Warrior attacks, you may have its controller create a 1/1 white Warrior 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.