The last few pages of the scripture had an extensive record for the requirements of executing the "art of Split Soul".
First of all, the execution of the art on the soul of the person who had been scattered must be as short as possible. Theoretically speaking, if the art was executed at the time of death, it would be the best option.
Next, the primordial spirit of the person who was executing the art should be as powerful as it could be. Otherwise, he would not be able to endure the pain of heavenly thunder striking down on him. The heavenly thunder would be able to shatter one's primordial spirit instead of diving it in half! If the spirit and soul were scattered, then there was no need to talk about saving someone else.
Lastly, both the executioner and subject needed to have a powerful spiritual link. That is to say, they were required to have deep feelings for each other.
