the easiest way to kill him I have found is get the vial of blood and the second book from the librarian(sp), run out and get the dragon scales, as soon as you have the scales jump behind the blood altar and hit the "I" key go to the inventory and find the book, and read it, find the spell and turn Amdusias back to human form, stay as far back behind the alter as you can, don't worry you can't fall, use Magic Blast on him to kill him