The volcanic activity that had sustained the Gorgon-Walkers for millennia began to wane. The Earth's crust thickened, and the surface temperature plummeted as the last of the Impact's heat dissipated into space. This was the "Great Cooling," a period that forced the most radical evolutionary shifts in the history of the Cinder Epoch. The Gorgon-Walkers, once reliant on external heat, had to internalize their furnaces or face extinction. The air became so cold that it would shatter the silica hides of the old-generation Walkers, leaving them to crumble into dust as they stood.
Their bodies became more compact, their legs shorter and thicker to retain heat. The bioluminescent sacs migrated deeper into their chest cavities, shielded by thick layers of fatty tissue and reinforced bone. This transition turned them from graceful, spindly wonders into massive, hulking juggernauts of muscle and armored plate. Their skin darkened to absorb what little light reached the surface, and they developed a thick, wool-like coating of metallic fibers that trapped air and heat. This wasn't just survival; it was a complete redesign of the Gorgon blueprint. The titans were becoming walking batteries, storing every joule of energy they could find.
This era saw the rise of the Cryo-Gorgons. These variants evolved the ability to absorb heat from their surroundings so efficiently that they left a trail of frost in their wake. By freezing the moisture in the air, they created their own icy terrain, giving them a home-field advantage against the warmth-seeking Harvesters. They could flash-freeze a rival simply by standing near it, drawing the thermal energy out of the opponent's body to fuel their own. The Cryo-Gorgons were the ghosts of the tundra, moving silently through the snowstorms, their presence marked only by the sudden, lethal drop in temperature that preceded their arrival.
The scarcity of heat led to the first instances of cannibalism among the Gorgon-Walkers. They no longer fought for vents; they fought for each other's internal "spark." A fallen Walker was a feast of thermal energy that could sustain a pack for a year. This period of starvation and cold refined the species, culling the weak and leaving only the most efficient killing machines. They developed "Heat-Senses," allowing them to see the infrared glow of a living heart through miles of blizzard. The hunt became a desperate, high-stakes game where the loser was not just eaten, but drained of their very warmth until they were nothing but a frozen husk.
The Great Cooling also forced the monsters to develop communal behaviors. For the first time, Gorgon-Walkers were seen huddling together in massive "Heat-Circles," sharing their internal warmth to survive the harshest winters. This social evolution was a byproduct of necessity, but it led to a primitive form of culture. They began to recognize kin, and the strongest among them would take the outer positions of the circle to protect the younger ones. The monsters were learning that in a world of ice, isolation was a death sentence. The Cinder Epoch was hardening them, turning them into a unified force that could withstand the death of the sun itself.