Suppose the protagonist of a novel led the story to a grand finale

Tatoeba Shōsetsu no Shujinkō ga Monogatari o Daidan'en ni Michibiita Yō na Asa (たとえば小説の主人公が物語を大団円に導いたような朝)

Marie realizes a Demon Lord is something Lloyd is allowed to fight. Lloyd finds Allan hiding from Abbadon's locust monsters and Allan is encouraged to act like a real soldier and fight. Alka later destroys the monsters for ruining her romantic plans for Lloyd. Chrome, Riho and Selen fight Merthohan, who is turned into a locust hybrid. Lloyd arrives and while appealing to Merthohan's desire to be a true soldier, defeats him with a slap. 

Marie then asks him to clean the dirt from the king's body, which he does, not knowing his cleansing rune is so powerful it purges Abbadon from the king's body. The next day, Lloyd's brother Shōma arrives but disappears before Alka sees him. Chrome rejoins the army while Merthohan is exiled to Kunlun. With the king cured, Marie decides to remain a witch. 

Grateful that Lloyd helped him, Allan declares Lloyd his master and gets him admitted to the academy. Alka clashes with Selen over Lloyd and realizes her belt is a powerful protective relic that went missing from Kunlun years ago. Annoyed with everyone, Marie banishes Alka back to Kunlun through her crystal and sends Lloyd and his friends to school.