I Hunt Monsters Pocket Manga Volume 1 (Pocket Magna)

The Enchanted Seal has been broken! Discovering he is heir to the legacy of the Warlock clan, William Warlock assumes the guardianship against the forces of the underworld too late to prevent the escape of the Queen of the Undead and her minions. They are out on a quest to conquer the world, but first they have a score to settle with the Warlock heir. With the help of the sorceress Aarna and the vampire Delilah, William races to recapture werewolves, zombies, demons and more and stay alive long enough to restore his family's protection of Earth.