noun
demon world; realm of demons
Refers to a supernatural realm inhabited by demons, evil spirits, or dark forces, often in fantasy, mythology, or fiction.
そのゲームでは、勇者が魔界に乗り込む。
In that game, the hero ventures into the demon world.
魔界から現れた怪物が村を襲った。
A monster that appeared from the demon world attacked the village.