Lawrence Phoenix was twitching all over, foaming at the mouth, and eventually died, all of which Lu Heng witnessed through the camera.
The twitching and foaming at the mouth were adverse reactions caused by mental shock.
Spiritual Skills do indeed cause a certain degree of mental shock to targets, which in severe cases can result in mental breakdown, brain damage, or even death.
These conclusions have been accurately drawn from research in spiritual ability and medicine.
Not only humans, but all organisms will exhibit varying degrees of response when subjected to Spiritual Skills, from a medical standpoint.
The lower the Spiritual Attribute of an organism, the higher the likelihood of injury from a mental shock.
If an experiment is done on mice, a mental shock from a C-level spiritual skill would instantly cause brain death.
This is because the mouse's Spiritual Attribute is too low to withstand the mental shock from C-level skills.
The same applies to humans.