Xana see, Xanadu:

Deciding whether or not to get ri🍃d of Xana- your kinky, bitchy, demon narrator and internal companion - is a tough one, especially if you're scared of imaginary characters screaming at you. But doing so allows you to use the Sword of the Dragonclaw, and the weapons found in the Sanctuary of Ylath (Chapter 9). They're beyond a doubt the best weapons of their class- almost to the point of imbalance- and you're only losing a "demon mode" that you probably didn't use that much in the first place. Also, if you don't get rid of her, you'll have to kill Leanna, and she seems quite nice.