in the book that comes with the trilogy on page 12 the first things it say are that Fizzlethorpe Bristlebane and Cazic thule next came to norrath
so that means that fizzlethorpe isn't bristlbane's surname that they are two different "gods"

No longer the pushover of Velious era, Bristlebane is a force to be reckoned with, leader of all that is mischievous in his mind-boggling Plane.
Arcane Maul of Celestial Destiny
Blazing Bracers of Discovery
Ensorcelled Great Sword of the Night
Fists of Fate
Flowing Cloak of Deceit
Mace of Mad Mayhem
Mystical Robe of the Zenith
Pendant of Cryptic Omens
Plated Boots of Ill Fates
Ruinous Blade of Annihilation
Shimmering Bauble of Trickery
TriXim, Dagger of the King