Okay, so let me explain this one. This post contains SPOILERS. It’s THEORY TIME!
We know by now that D was birthed by his mother Mina the Fair, fathered by Dracula AKA the Sacred Ancestor, and that he has been genetically engineered and altered/perfected by the latter. We also know that D was his only success, as is reiterated constantly throughout the books. From what we gather when D comes across secret vampire labs, the Sacred Ancestor’s goal was to perfect the Nobility; make them less dependent on blood, have them able to walk in sunlight and be not as affected by weaknesses like running water, etc. But all in all, from what we learn about Dracula (we can assume this is his name, as D is short for it), he is not a bad guy. In fact, he seems like a pretty stand-up dude. In Pale Fallen Angel, Fisher Lagoon had only good things to say about him. Left Hand regaled old stories about him in Demon Deathchase which painted him in a good light. In The Stuff of Dreams, the protagonist was comforted by his presence in her dream. All in all, we have really only heard positive things about him, other than his horrific experimentation habits as seen in Twin-Shadowed Knight. But they are for a lofty goal…to make a new race of Nobles like D, who will have all the power and authority of the Nobility, but can live among humans as equals with none of their weaknesses.
Here is my prediction: D may or may not know this, but he has a purpose: his purpose is to kill all the Nobles. It’s taking a while, which is buying Dracula the time to perfect his experiments and create more dhampirs like D (or altered Nobles, like Byron Balazs, but perfected). When he is finally finished, and the last pure Noble is dead, only Dracula will remain. He will have created a better world…a world in which Nobility (or half-Nobles) can live in peace among humans…but for his crimes and heinous experiments, he may not enjoy this paradise. He must be put to death by the only person who can kill him: D. Like Moses, he will lead his people to the promised land, but he can never experience it, because he will never be worthy. But D will be…because he was his only success.
…..yeah I am sure Kikuchi will come up with something much deeper and WAY better, but a girl can theorize!