Dvucca Isle SP is actually a lot of fun for a WHM. With a good backline you can contribute a little more. Banish III hitting for 1200 is nice if you have the mp spare.
Not sure whether Banish helps with removing penalties on undead here too? I rarely ever see the damage party members inflict so it's hard to say. Also Qutrub seem pretty weak to most damage, just a hell of a lot of HP.
[Edit] Guessing it does then