Gaea's Vengeful Wrath

(You may cast a legendary sorcery only if you control
a legendary creature or planeswalker.)
This spell can't be countered.
Create Gaea, a legendary 10/10 green Elemental
Avatar creature token with hexproof and trample.
If you're dealt damage by a source you don't
control this turn, green creatures you control get
+3/+3 and gain haste until end of turn.