You Xi Wang was using the spirit energy stored inside his dantian to cover up his body and found some relief from the pain. The amount of spirit energy he had was higher than that of the normal cultivators. The system wanted to say something but if he was to cause a disturbance at this movement, that will be spelling You Xi Wang's death.
The system used soul force to manipulate all the shredded flesh on the ground. The flesh of a cultivator was tempered by the spirit energy. The whole world was made up of spirit energy, well cultivation was already defying science, this was only a perception of the cultivators. It was not without any base to it.
As the people progress on their path of cultivation they will all be outlasting the life span of a common human. Even the hospitals used spirit energy manipulation for the treatments. When the people were injured with physical injuries they would be provided with spirit energy directly to restore the wounds.