Diablo as seen in anime (Image via Ajia-do) In How Not to Summon a Demon Lord, Diablo's ridiculously high mana pool allows him to cast strong spells continuously without the fear of running out.

Beelzebub, a powerful devil and the Demon Lord’s son from Black Clover, is sent to Earth with a mission to destroy humanity. However, he becomes enamored with Oga, considering him the best student.