Just beat him on my 2nd try, after 9 left on my first. Once again, I used an elf paladin with a dragon shield.
My most important buy was a second schaudenfaud potion which was incredibly important. Fought at level 6 and leveled up to level 7, and used only two undead heals. The most scary moment was when I could not sustain another hit from the indomitable and he had no protections left. Fortunately, Dracul was there to save the day with a last minute blood swell.
Since I'm interested to see other peoples strategies please post how you beat it.
Also, I have finally beaten every quest and dungeon at least once!!!!!!!!
I speak chaos.