The Record of a Fallen Vampire [Manga]

Having cast aside his Kingdom of the Night a thousand years ago, the vampire king Strauss wanders the lands in search of the place where his queen was sealed. Dogged by the dhampires who are out to kill him, Strauss is fighting against time as he must continuously face humanity’s curse, the Black Swan.

Initially, the story focuses on introducing Strauss and his quest for the seal, while fighting against the Black Swan and the dhampires. The main plot, which gradually emerges after volume two,² revolves around repelling an alien invasion. The humans plan to use Strauss’ powers and Adelheid’s powers to repel the invaders before having the Black Swan finally dispose of them.

Bridget, Strauss and Adelheid use flashbacks to convey their perspective on the events a thousand years ago.

(taken from Wikipedia)