Nature's New Order
The quick-mouthed, crafty king of the bandits. Nobody knows why he is called "Nightmare".
Nightmare Tomas first crossed paths with the party on their way to the Old Capitol. At the time, he was accompanied by a group of quasi-real bandits, and although he was troublesome, he let the party leave peacefully after defeating his illusions.
The next time they met was after the party had defeated The Rider, and Nightmare had changed. No longer the bandit king from before, this new Nightmare had dropped his former name of Tomas. After confiscating the Cube of Infinite Knowledge from Theydrin (although leaving the Battery) Nightmare kidnapped the party, and took them via carriage for many days to an arena filled with Goblings.
In the arena, the party was forced to compete in bizarre competitions conjured by Meleader and his Metoo, with Nightmare pulling the strings from the spectators box. Eventually the party escaped their cells, and Theydrin was able to convince the Goblings leadership to turn against Nightmare. Before they did however, Meleader shared memories of Nightmare before he was corrupted. The details are unclear, but Nightmare brought the Goblings from another time, and helped build a society for them beneath the arena where he would provide for them, presumably by raiding. Nightmare had only been corrupted for a week or so before he captured the party.
Once the party turned the table on him however, Nightmare transformed into a demonic form, and set the majority of the Goblings ablaze before fleeing. The next time the party would encounter him, Nightmare was at the portal to the plane of Fire, within the Temple of the Ancients. He tried to hinder the parties investigation of the temple and portal, but he ultimately met his demise when he tried to toy with the party and found his fortunes reversed when a well-timed counter-spell from Von Nocen left him vulnerable to attack from Bram Boulderhammer & Farin Oinson