Some of them are quite clever. Just — you know.

[ Inexperienced? Unfocused? Incapable of getting out of their own way? Voryn and Set, once again pot-and-kettling. ]

The soul itself is made of multiple parts, and the ẖt has to exist for the soul to have any intelligence or the chance to be judged. The body must be whole, so the removal of the head is the final manner in which a human was to be condemned to oblivion. It is their second death, and termination of all hope of reaching Duat.