Uldrak the Tinker

A spined devil, who once was an empyrean -- a titan in service of Surtur. Seeking to win glory for his lord, he quested into Avernus to slay Tiamat and not only failed, but was cursed. Now he is a spined devil, forced to live within his own helmet and never wander too far from it unless he can spill the blood of Tiamat upon the sands of Avernus.

Makes a living as a scavenger, scrounger, and tinker. Owns a set of astral pistons that he wants the party to trade to Arkhan the Cruel in exchange for the reliquary of Tiamat's blood around Arkhan's neck.