Zatch Bell!

The Dark Mamodo (1x5)

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The mysterious man, Renji, reveals he is the book user of the dog Mamodo, Gofure. Zatch is unwilling to fight, believing he is a monster and Kiyo would be better off without him. The pair easily defeat Renji and burn his book. During the battle, the pair are revealed to be Sherry Belmont and Brago. Using "Gravirei", they demand Kiyo to surrender his book or be killed by the spell. Kiyo refuses saying Zatch is his friend who saved him and that he will repay the favour. The pair prepare to use their strongest spell, "Gigano Reis". Zatch happy Kiyo considers him a friend, regains the will to fight. Using "Zaker" they were able to cancel the Brago's spell but Kiyo losses consciousness in the blast. Sherry decides to spare Kiyo and Zatch and leave saying they shall return for Zatch's book one day.