Ten thousand years ago, the cultivation world underwent the “Descent of Rules”: an unknown entity implanted bizarre rules into the laws of heaven and earth.
Since then, “rule domains” may exist in any corner of the world. Those who break the rules may suffer a decline in cultivation at best, or die suddenly or transform into bizarre creatures at worst.
Ordinary people cannot see the rules and can only test them with human lives. The major sects have specialists known as “Rule Breakers,” but their death rate is extremely high.