If I remember right, this is the one where you summon three mob-boss type ghosts on your own in quick succession.
The strategy for this is to shield! Shield a lot. If you're balance, now is time to get out those elemental and spirit shields. If you'e not balance, pack whatever shields you have. When you shield, you can deflect most of the damage that is dealt against you, letting you survive longer.
After a battle, if you've got low health, use a potion. Potions are a wonderful thing when it comes to consecutive battling, because they heal all your status problems, like health and mana, with one click.