Demon Magic (悪魔, Akuma), also translated as Demon or Devil and known as Fiend in the English version of some video games, is an Alignment and one of the four types of Magic users.
It is strong against the Illusion Magic Alignment and weak against the White Magic Alignment.
It is briefly mentioned in the manga and found in the games Yu-Gi-Oh! Dark Duel Stories, Yu-Gi-Oh! The Sacred Cards, Yu-Gi-Oh! Reshef of Destruction, and Yu-Gi-Oh! Duel Monsters 4: Battle of Great Duelist.
The Type, Fiend, is based on this Alignment.