Lernaean the Ancient

Whenever you cast an ancient spell, all
hydras you control gain +2/-1 until end of
turn. If this ability is triggered 4 or more
times in one turn, then give all hydras you control +1/+6 until end of turn. If this ability is triggered 8 or more times, then all hydras you control get +4/-1, trample, and double strike until end of turn.