Noelle and the other Black Bulls head to Racquey to do some training, when Noelle hears a mysterious voice. Shortly after, the Black Bulls are reunited with Kahono and Kiato. The siblings ask them for help and they head down to the Underwater Temple. There, Gifso explains that a creature called the guardian has gone berserk, so in order to quell its rage, Kahono and Kiato need to present it with their song and dance. Gifso asks the Black Bulls to act as their bodyguards and Yami appoints Noelle and Finral for the job.

Asta and Noelle are captured along with Nero and they head toward the strong magic region near the border when Captain Yami and Magna arrive. Captain Fuegoleon and Captain Nozel also show up, causing the Devil Believers to panic. The captains try to talk to the Devil Believers, but their distrust for them is just too strong. The Devil Believers try to bring their powers together in order to face the Magic Knight captains.

The War against the Spade Kingdom begins in earnest as the Heart Kingdom and Black Bulls come under attack by Dante and Vanica of the Dark Triad.