It can be pretty grindy at that point. I had 1 or 2 strong combat characters who were blessed and hasted and defended doorways until the tide of bodies waned. But this is a tedious process. I suppose you could stock up on energy potions and supplant that with liberal use of Wall of Blades.
I also never used Avatar. Seems like a waste of spell points to me, if you have a full party of 6 characters.