A delegation of Roseguard Imperial Knights summons Seiya and the others to a nearby fortress, where a wing of demon houseflies is attacking from the air. Seiya offers his help, but when he butts heads with the knights' leader, things turn ugly.

Mash and Elulu demonstrate some new skills they picked up, and Aria is horrified to learn that Seiya is training with Mitis. Back on Gaeabrande, Rosalie has gone off to challenge the flies alone, and Seiya and company must go to her rescue.

Kilkapul summons a nightmarish reaper to eliminate Seiya and the others, and not even retreating to the Divine Realm is enough to stop its advance. After Mash and Elulu improve their skills, Rista resolves to step up her own game, as well.