Morrigan's most powerful special attack is called Eternal Slumber. You can execute this cheat by pressing Square, Circle, <-, Triangle, R2. This attack will shoot out a heart that moves towards the target at a rather slow speed, so use it wisely. It cannot be blocked and can only dodged by jumping over.

Note: This attack requires 3 special gauges and cannot be execute in beginner mode because it only allows 2 special gauges.