I forgot the name of the manga abt a boy is the only one that can use dark magic? and he's actually demon king?
http://www.mangago.me/read-manga/konya_mo_nemurenai/ ?
http://www.mangago.me/read-manga/hataraku_maousama/?
I forgot the name of the manga abt a boy is the only one that can use dark magic? and he's actually demon king?