Rules.
They were not the rules, neither the laws nor the regulations that Yang Lujia knew about. They were a different concept here in this world. Rules, here, were reality-breaking, almost inanimate, things that could possibly turn a world upside down. The rules themselves could break the balance, the peace—if utilized by humans. They were like the cause of why everything would break out into war.
They were quite the same as the rules he knew in his previous on Earth. They kept the world sane. They kept the world in harmony. Not until it fell into the manipulation of those who had dark or evil intentions.
"Those who have only reached the Saint Realm could utilize these rules. In the lower stages of our cultivation, we could not utilize them due to the fact that our souls are not yet prepared. Not yet prepared to control or manipulate them as they like."