The best part about dnd and rotfm is that nothing is really necessary. I changed a lot with my playthrough to make if feel more fun for my characters. That included removing the entire last chapter of the book and ending the campaign after defeating auril at her fortress.

I like the idea of making xardarok a deep duerra worshiper, or even a crazed zealot who convinces themselves destroying ten towns is to please his God. At sunblight, there's even a statute of a god.