Demonoid

Demonoid (人魔族) is a catch-all term for Humans who have undergone the process of monsterization and become Majin as a result. Their specific monster nature varies from person to person, hence why a blanket term is used.

Majinization (Monsterization)
Majinization occurs due to a mutation brought on by high magicule exposure, magic rituals, or other unique circumstances.

Properties
Humans who become demonoids possess a large store of magicules and, like all monsters, have a constitution reliant on them. Becoming a Majin comes with an innate affinity for casting magic as well as an extremely high tolerance towards magicules and magic, incomparable to that of their previous self. However, by becoming demonic beings, they are capable of being completely annihilated by Holy Magic.