Purge is a great ability that acts different for allies and enemies. When you apply this spell to ally it removes one debuff and gains extra magic defense. But when you use this ability against enemy it removes one positive buff from the target. As you see this spell will help a lot in PvP when your enemy is under an effect of powerful buff that doesn’t allow you to act. For example enemy can have buff that gains him temporary resistance to stun. Use Purge and this buff will be removed.
List of abilities that can be used before Purge in order to benifit from Purge combo effects.