Sigrid, the Blade-Blossom

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 this ability only during
combat.