The Cold Fire, like the Illusory Fire, is the first wisp of fire energy in the world, and upon shattering, it produces a fragment.
Moreover, the subsequent process is like the Illusory Fire, descending from the sky and landing here, although it wasn't called the Zero-Degree Plain at the time. It was just a plain, and then the Cold Fire froze the surroundings.
Of course, a single Cold Fire doesn't possess such a great ability to transform an environment into a forbidden zone. It was only after subsequent tectonic movements, where a mountain collapsed during the earth's movement and precisely struck the Cold Fire. After a series of movements, the Cold Fire used its freezing power to create a vast ice layer in the instant the mountain pressed down, forming the space within the ice crevice today.
