Savage Rampaging Ape → Eight-Armed Mad Ape → Primeval Gray Ape... Chen Fan, along with tens of thousands of others, was transported to a world of beast mastery. He discovered that he could not only see the evolutionary paths and methods of beasts but also their preferences and weaknesses. Moreover, he could freely enter and exit his beast space, which contained four doors connecting to four unknown worlds. ------------------------ Over two thousand years ago, when two moons appeared in the sky, this world became a world of monsters. Mountains, rivers, grass, and trees could transform into spirits, and ancient swords and knives could give birth to spirits. Beasts, demons, giants, elves, insectoids... they compressed the living space of humans to the extreme. It wasn't until the appearance of beast masters, who could sign beast contracts with monsters, that humans found a new lease on life.