The soul-blood agreement was an old secret law, created by the Soul-Blood Emperor to maintain his followers' loyalty. But the agreement was so cruel that most beings would rather die than to sign it, thus it was gradually forgotten. Until now, very few people knew how to make a soul-blood agreement, but Zhang Yan did, which had surprised the Anti-Soul Beast.

In fact, he knew it from the Purifying Lotus who had witnessed the process of making a soul-blood agreement. With such secret law, confidence sat in his heart.

He did not reply the Anti-Soul Beast's roar and rushed back to the Fengdu City. It took him half a day to arrive at the city at noon. The city was in bright with a lot of people coming and going.

No one noticed this young boy, because he was still unknown among the city. Therefore, he could returned to his room in the inn without disturbing Yan Luo and Meng Yao. Sitting quietly, he was waiting for the answer of the beast.

The beast's weakness was obvious now. It was such a miracle for the beast to live for more than a million years, though losing its body under the suppress of the stone. However, Zhang Yan owned the stone now, so the beast could keep his soul alive forever as before, in another word, it's soul would definitely be devoured by the stone. Therefore, he was quite sure that the beast dared not to refuse his request in order to live.

Sure enough, only after few minutes, the beast called him through soul energy.

He felt the vibration in the stone and fetched it from his Knowledge Ocean. The foursquare stone flew into his hand. He began to communicate with the beast through soul energy, "What do you think of my proposal?"

"Can I be your guardian beast?" It prayed.

"Guardian beast?" He shook his head and bluntly said, "Even the complete you are not qualified to be my guardian beast, let alone only your soul!"

The concept of guardian beast was born in the ancient times when all the races in the Renhuang Realm united together to fight against the Ghost Race. At that time, the Human Race and the Devil Race were the fight's backbone with intimate relationship, so the devils volunteered to help humans as their guardian beasts.

There were no agreements between the humans and the devils, but only verbal promise. The devils used to be committed to their promise, so most of them would protect humans as much as possible. But in the later period, the humans' power was getting bigger and bigger, so was their desire to control and they were not satisfied with the need to own a guardian beast, but petted the devils or even slaved them.

The strength of the devils was getting stronger too. Without the common enemyGhost Race, the devils were unwilling to be a human pet and be bullied anymore. Even in order to compete for the territory, the Human Race and the Devil Race started fight, and untill the generation of the Soul- Blood Emperor, he invented the soul-blood agreement to control the devils.

It was said that the emperor was besieged and killed by the many devil kings later and even the soul-blood agreement was destroyed. The lotus, however, had been through that period of time and remembered the agreement.