His brilliance and obsession with himself were rivaled perhaps only by his guildmaster, Niv-Mizzet. Within the last few years, he hatched a scheme that, if it worked, would have devastated an enormous amount of the cities of Ravnica. Hiding his plans within the reclamation zone of the Utvara Valley, he worked diligently; exploiting his servants every way he could so that he could bring what he thought would bring the City to his knees, even Niv-Mizzet. His plan involved three dragon eggs he had uncovered years before. Ravnican dragons, in truly ancient times, were immense and god-like, warring and devastating to nearly as great an extent as the Elders of Dominaria. In modern times, the only dragons are a few feeble remnants in the form of drakes, and of course the leader of the League. Hauc heated the eggs up for years, hoping to hatch them and then take over their minds, gaining control of demigods, thus enabling him to smite the Firemind and raze the City, letting him rule from the ashes. Were it not for Agrus Kos, an Orzhov friend of his named Pivlic, and several other primary characters of Guildpact, he may very well have done so.
When the baroness Teysa Karlov claimed her inheritance and moved to Utvara, it spurred him into accelerating his plot. He managed to hatch and enslave an enormous hatchling. However, Teysa and Kos replicated the spell he had used in order to gain control of one of the other hatchlings for themselves. Then Teysa and Gruul chieftain Vor Golozar rode this dragon, followed by Kos and Izzet League courier Crixizix in an Izzet observation sphere. Then the blue dragon that Zomaj controlled was killed by the one controlled by Teysa. He was killed when he was crushed beneath it. All though the group had ended the threat he posed, Kos was killed in the process.