Gwen, Arcane Mystic

: You may play Gwen, Arcane Mystic from your graveyard or exile as if she had Flash by sacrificing two nontoken nonlegendary permanents.
+2: Gwen, Arcane Mystic deals 2 damage to all players. You gain 4 life and put a +1/+1 counter on a creature you control.
-8: Until end of turn creatures you control gain Haste, Menace, First strike, and Trample, and get +1/+1.