Trinity Seven: Heavens Library & Crimson Lord Trinity Seven Movie - Tenkuu Toshokan to Shinku no Maou English Subbed

Arata, Lilith and the rest of the Trinity Seven ace off against their greatest enemy; Lilith’s own father, who is revealed to be the strongest Demon Lord. He challenges Arata who is now a Demon Lord candidate.

(Source: Anime News Network)