that dude is modified to produce sedatives for anything you can imagine like kidnaping and other things, essentially making him property barely living at this point. they gradually produce more and more powerful sedatives as time passes but at some point they just drop dead cuz of all the increasingly potent stuff they are producing essentially killing them selfs

something to note is that they are only part of a machine thats how they became that way, but if you're fully turned into this things and if you still have your essential organs you can survive without the machine and still produce the sedative although in much smaller quantities and potency

it would be interesting to make a protagonist of a story like this, the typical bottom of the barrel type situation