In the first place Wang Wei did not plan to kill Wu Ming. Although he is the kind of person that can do anything for his goal, he still knows gratitude and has a somewhat moral bottom line.
Furthermore, Wang Wei is the kind of person that knows when to repay his karma. The Formation Rune Body method is of great help to his future plan. He would never be able to acquire it without the help of Wu Ming.
After pondering for a few moments, Wang Wei took two jade talismans from his space ring. In the first talisman, he copied the entire book left by Wu Ye--including the journal part of it.
Then, in the second part, he recorded some ideas he had after reading about the Formation Rune Body. He provided Wu Ming with a few ideas that he thought about or read about from his past life.
