魔界 is read as まかい (makai) and means demon world.
まかい
makai
まかいむら
Ghosts 'n Goblins (video game)
まほう
magic
まじゅつ
black magic
まりょく
magical powers
まほうびん
thermos bottle
まじょ
witch
ま
-crazed person
まほうつかい
magician
まもの
demon
まじょがり
witch hunt
まじゅつてきけいざいがく
voodoo economics
まほうがっこう
School of Witchcraft and Wizardry