The spirit beasts that had lost their beast king were like a swarm of dragons without a leader, and soon all the territories were invaded by humans.
The worst thing was the human emperor back then was determined to annihilate the spirit beasts. But he was also afraid that the spirit beasts would regain equal privileged strength as humans. So, he had poisoned the water sources of the spirit beasts and prohibited them from leaving their territory.
In that case, there were only two options, the beasts would either die of thirst or drink the water and limit the speed of their cultivation.
In other words... the spirit beasts that could break through the first level in one year would need ten years to achieve that after drinking the water!
The emperor also knew that spirit beasts generally have a long lifespan. The spirit beasts also have certain strengths that could be utilized by humans. They were growing slowly and would not threaten humans.
