Deep in the Alps, hidden from view from mortal eyes, early 19th century.
Vampires exist and have since the fall of Atlantis. The ancient Titans the leaders of the Dragons sent to Earth under the command of Chronos, had placed Their nanites in human hosts. To create additional foot soldiers to fight the Atlantis installation on this world.
However, unlike the Nanites of the last Prince of Atlantis, these were not intended for humans. They required the host body to consume a special diet of liquid protein, Milk, and Blood being the best sources. They were weak to direct radiation such as sunlight. Since these nanites were designed for reptiles, who processed direct sunlight to heat the core of their bodies, the nanites would respond badly in the bodies of mammals such as humans. In a few cases, the nanites would explode or catch fire if the person was in direct sunlight for too long.
At the same time, the nanites allowed the transfer of conscience from a Dragon to a human host. It was intended to spy on Human settlements and space-stations. It was a core part of the plan to destroy the human galactic empire. Of which they were fairly certain worked, although no rescue force either a dragon or human has yet to be sent. They are sure there was no true victor, and galactic civilization most likely fell all those years ago.
Chronos upon his death had his mind placed inside such a human, however, because of the timing, and because Zeus Cremated the body. Chronos Host was not fully erased and replaced. The Host body and the Dragon mind merged, causing him to be insane most of the time and unable to really plan much more than ways to destroy empires and civilizations.
He spoke to the gathered vampires his Titans. “We must bring chaos back to our world, our crusade to make our world great again, must be unleashed upon the world, now, we cannot wait another 500 years with the rate human technology is being developed.” we must move out of the shadows, and rule the humans directly. We must make a kingdom in the sun, and an empire of our choosing.
The various Titans agreed, chief among them and Chronos' main advisor a Human Vampire who was once the Prince of Romania, his mind, and his skills as a leader caused him to be recognized by all the gathered titans. Vlad the Dragon whose still human mind, had drafted a plan to which all the gathered titans, and Chronos could agree was brilliant and possibly better than any previous plan they had ever done. Vampires were going to rule Europe openly in a hundred years.
