Hellsing Ultimate

For over a century, the mysterious Hellsing Organization has been secretly protecting the British Empire from the undead. When Sir Integra Hellsing succeeded as the head of the organization, she also inherited the ultimate weapon against these supernatural enemies: Alucard, a rogue vampire possessing mysterious and frightening powers. Now, Hellsing must deal with a more dangerous threat than vampires.

Tags: anime, anti hero, based on manga