Arrendis is correct and that’s just the sad reality of the matter. Unless a person is recovered and receives medical and cybernetic intervention very soon after being processed into a True Slave the technology seems to fully subsume and replace whoever they were before. If any fragment of them remains I am sure they would welcome death as a mercy. The best that can be done is grant them that so they need not continue existing and cannot be leveraged by their master into visiting the same unfortunate fate on other innocents.
These people are already dead and gone, their body just doesn’t know it.