Hellsing Ultimate is an anime series based on the manga created by Kouta Hirano. It follows the Hellsing Organization, a secret group dedicated to hunting and destroying supernatural threats, particularly vampires. The story centers on Alucard, a powerful vampire who works for the organization, and Seras Victoria, a former police officer turned vampire. The series is known for its dark themes, intense action, and unique animation style. It explores the conflict between the Hellsing Organization and various supernatural enemies, including the Millennium organization, which seeks to unleash chaos. The narrative delves into themes of morality, power, and the nature of humanity.