Vampire Juuji Kai

Vampire King Akabara Strauss lost his kingdom and queen long ago. Humans could not kill the queen, so they trapped her and placed numerous false seals to hide her real location. Akabara has spent centuries searching for her despite constant threats from dhampires. His search becomes more complicated with the arrival of the Black Swan, an entity that inhabits a human girl every fifty years. Each new host gains the ability to destroy the Vampire King and his queen, and with each cycle, the Black Swan grows stronger. The 49th incarnation may finally succeed in ending Akabara.