In the thick of the French Revolution, members of the so-called lower classes are rising up to fight inequality. Meanwhile, Richter Belmont senses a far grimmer and greater danger. He's picked up his family's long-held tradition of vampire hunting, a vocation that goes back almost as long as a vampiric life span (in other words, forever) but he's never seen anything quite like what he's witnessing now.

In season 2, the legendary Alucard, Richter Belmont, and his band of vampire hunters are in a desperate race against time. Erzsebet Báthory, the Vampire Messiah, who already seems invincible, seeks the full power of the goddess Sekhmet so she can plunge the world into endless darkness and terror

https://www.themoviedb.org/tv/123548-castlevania-nocturne