The Ancient Invasion of the Five Rats

In this chaotic world of the Warring States Period, a race that was supposed to decline, the "Ancient Tribe", established the Skyfall Empire in the secret rainforest of the southern continent. They have very powerful power, and can make other races unable to fight with just brute force. Facing these re-emerging ancient tribes, how can the cats and mice* and other kingdoms fight against the powerful ancient tribe? What will be the fate of the world? This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.