Oct. 30th, 2019
The world)

In 1999, the world ended. Humanity, swept up in conflicts and wars, finally went too far and a nuclear holocaust swept the world, reducing much of it to waste and humanity to try and survive in the nightmare they had created. Years turned to decades turned to centuries, and instead of picking up the pieces, humanity fell to savagery.
Which was when the vampires stepped in. Their exact origin wasn't clear, and some claimed that they had been around since the beginning of mankind, but regardless what was clear was that they had been waiting for this moment. Aware of the path humanity was taking, the vampires had created their own plans and resources, enough to rebuild the ruined world and craft a new one from the remains. With themselves as the rulers of it.
Led by the first of them, Dracula, known as their Sacred Ancestor, they created a society ruled by vampires and named themselves the Nobility. While they subjugated humanity, they did succeed in restoring the world and finding ways to better it, advancing science to levels beyond what was originally lost. They created space travel, artificial intelligence, genetic manipulation, cybernetics, advanced weaponry and defences, and complex systems to control almost every aspect of the world around them.
But it was far from benevolent. For all that the Nobles, as they called themselves, created technologies that could benefit the world, they also seemed to revel in their dominance of it. They would genetically engineer monstrous creatures and release them into the world out of sport, uncaring what threat they might present to others, and even on creating ways that meant they could sustain themselves without needing to feed on humans, many of them still preferred the hunt and the power that came from treating humans as prey.
For a while this was the world that humans were forced to endure, but around the year 4000, it became clear that the Nobility, despite all their efforts, were declining. Even with their powers and advances, they were few and their numbers were dwindling. Humanity rose up against them and reclaimed the world for themselves once more, hunting and killing many of the vampires inhabiting their capital and driving others into hiding.
Now the year is 12,090 and the once great inventions of the Nobles are often forgotten and left where they stand, technologies forgotten in human memory and those Nobles that might still be able to make use of it few and far between. Humans try to eke out a living as much as they can in a world now inhabited by strange, monstrous creatures, making use of what technologies still available to them.
Hunters have risen in numbers as a result of this new world, men and women who make it their business to protect others from the numerous threats on the frontier, and none are as skilled as those hunters that specialise in hunting vampires.
D's history)

D was born as a part of the Sacred Ancestor's experiments into combining the Nobility with humans in an attempt to halt the inevitable decline of vampires. One half of a pair of conjoined twins, D was unaware of his brother through most of his life, as they were separated and the second D kept confined. At some point in his past D was given the parasite in his left hand and departed the research facility that he was born in, believing he had destroyed it.
Beyond this and a few other minor points, D's past is largely unknown. While it is never stated outright, it is heavily implied that D's father is the Sacred Ancestor himself and this implication is often used to explain why D is able to go so far above and beyond what other vampires and dhampirs are capable of. It's also implied that D spent some time as a possible lord of the Nobility himself prior to receiving the parasite and that he has been around for roughly 10,000 years.
D's relationship with the Sacred Ancestor is also difficult to pin down; by turns he seems angered by what has been done in the quest to prolong the reign of the Nobility and other times he is almost melancholic and reflective when speaking of him.
Regardless the relationship, one thing that is clear is that part of D's travels is a search for his creator, although what exactly he intends to do when he finds him is anyone's guess.