Heavens Library & Crimson Lord brings back Arata, Lilith and the rest of the Trinity Seven to face off against the greatest enemy in the history of the Trinity Seven; Lilith’s own father, who is revealed to be the strongest Demon Lord who challenges Arata who is now a Demon Lord candidate.
So an alternate world's 
Demon Lord has come here?
إذًا فقد أتى ملكٌ شيطانيّ من عالم بديلٍ إلى هنا؟
Ist das also ein Teufel
aus einer Parallelwelt?
¿El rey demonio de un mundo alterno?
¿El rey demonio de un mundo alternativo?
Le maître
de l’autre monde est là ?
È comparso il Signore dei Demoni 
di una dimensione parallela?
Então em um mundo alternativo
o Lorde Demônio veio até aqui?