I Became The Vampire Progenitor

Li De accidentally gets transported into a virtual game that won’t be released for another year. He becomes the vampire's progenitor, an ancient being hiding among humans to learn magic, and gains control of an ancient castle along with 200 bloodline descendants. Though he can still return to Earth temporarily, Li De faces a major challenge: in one year, the game’s public beta will begin, and players will enter the world. As a vampire, he must find a way to grow stronger and prepare his race to survive the impending arrival of these players, who could become a massive threat. This is the story of how a vampire progenitor and his descendants team up with humans to cultivate resources, master magic, and build a thriving community in order to withstand the coming storm. --- Kingdom-building, Fantasy world. [TL: Galactic Novels] — Description from novelcodex.org