Avacyn, Angel of Light

Eminence - As long as Avacyn is in the command
zone or on the battlefield, other Angel spells you
cast cost {1} less to cast.
Flying, Lifelink, Haste
Whenever three or more Angels you control die,
exile Avacyn, then return her to the battlefield transformed under her owner's control.
{2}, Sacrifice an Angel: Gain 3 life.