The Chronicles of Slovengris the Astral Wizard, Vol. 1.

From publisher blurb: The goal of The Chronicles is to present a framework for players to pursue an villainous scoundrel named Slovengris across multiple worlds or planes. Whether to pay back a personal vendetta, to collect on a myriad of bounties, to get their hands on Slovengris' supposed stash of artifacts, or to simply rid the universe of a sleaze ball (or some combination of the four), players will not lack a motive to track the scheming wizard. Volume 1 gets the party started with a short story titled The Origins of Slovengris, a backstory that brings Slovengris to life by hitting some of the highlights (or lowlights) of his past. The second part of Volume 1 is a 4th level adventure called The Vats of Aventhil. After yet another reckless getaway, Slovengris inadvertently finds himself on the characters' home world and wreaks havoc as he is wont to do. Local authorities enlist the aid of the player characters to stop mutant creatures harassing the countryside. Worlds collide.