Ok, so the novel's concept is that one day in the near future or maybe past, no clue if this is our Earth, humanity is imprisoned in a massive 'blood farm'/'blood plantation' and placed into dreamworlds.
These places are ran by the offspring of a MASSIVELY long (like 1,000+ feet) snakey, vampiric and demonic dragon from the abyss named Drak(DRAConic/DRACula). These reptilians have placed humans in the mind prison of dreams with their magic/physic abilities so that not only they are easier to drain of blood, but so that they can also control and manipulate the flavor of the blood by giving them scary, painful, pleasurable, or weird experiences, depending on the mood and cravings of Drak.
On top of this, they also make humans ageless, more resilient, and not really needing of any food or water by pumping them full of Drak's concentrated saliva and/or other bodily fluids. This also allows humans to be drained of like 80-90% of their blood without dying. They can also recoup full blood volume and red blood cell count within nearly a week.
Good news is that there are humans that broke out/been busted out and ones never farmed, they have made villages here and there and are trying to end this vampiric and demonic madness. The best helpers they have so far is very fit warrior with a massive 8 foot sword, his steed, a relatively small 'defective & defected' dragon, and a small robot companion.
Feel free to ask me more about this story, be it characters, setting(s), or lore.