The Kaigland Chronicles
Arcanus the dark mage joined up with the party in his own quest for power, which he needed to find his sister who had been lost in time. To this end he obtained the Book of Dark Matter, a tome that granted mastery over the strange energy source that claimed to be the stuff of life and death. At the end of Book II, Arcanus was thrown into the dimensional rift, and emerged in a room filled with other Arcanuses, all also seeking their sisters. It is rumored that Arcanus went on to have other adventures in other worlds, but whether that was the same Arcanus or not has never been determined.