system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter] What level of functionality would someone kissed by a dementor have?
gpt
Full on, soul eating kiss? "The lights are on, but no one's home." Biologically speaking everything is there, but the actual person is gone. The soul is a known property in the Potterverse, and dementors are capable of harming it directly. When they perform the kiss, the actual immortal essence of the targeted individual is literally snatched out of their body. Mechanically speaking all of their organs work, all of the neural pathways in their brain are still etched with their memories, but there is no more driving force. The body lives, the person is as dead as if you blew their head off with a shotgun.

As far as what the soulless body is capable of, many autonomous functions of the internal organs (blood circulation, breathing, etc.) would continue to run, and some reflex actions (eye dilation, limited pain response, etc.) would still happen. Beyond that, there really isn't much you can do with them. Practically speaking, the best function for a body kissed by a dementor would be as a source of donor organs.