There are many legends about zombies in folklore, but for the Cultivation World, these unconventional cultivators unite their souls and bodies through a unique process to gain immense power.
As a result, they cannot enter the cycle of reincarnation.
The method that David changed into is not really about cultivating as a zombie, but using the essence of a demon clan as a medicinal catalyst to turn his own body into a "zombie-like" state while his body and soul remain separate.
Whether the prohibition placed on David's soul can still work after the fusion of soul and body into one... can only be determined through actual manipulation.
There are two possibilities: first, the prohibition directly erupts when the soul and body fuse, annihilating David's soul.
The second is the prohibition's dissolution, and the soul fuses smoothly with the body.