In this world, everyone can use magic… and in a land called the Clover Kingdom, two young men, Asta and Yuno, strive to become the Wizard King, the greatest of all magic users. Asta and Yuno were abandoned together at a church in Hage, a village in the boonies, and lived as brothers from that day onward. For some reason, however, Asta never developed the ability to use magic, even when Yuno had already mastered wind magic. Now, at last, the boys are turning fifteen, the age at which children receive their own grimoires. Asta has high hopes that receiving his grimoire will awaken his latent ability to use magic, but when the time comes…

As life slowly returns to normal in the royal capital, the Wizard King reaches an uncomfortable conclusion about the invasion and how it came about.

Licht and Lumiere fight against the devil using incredibly powerful magic. But the devil has incredible regeneration powers and quickly heals himself, making him difficult to defeat. Asta witnesses the two powerful mages fighting and tries to figure out if he can use his anti-magic in a more useful way. He’s able to use a new power, but it’s so powerful that he’s having a hard time controlling it. Meanwhile, Yuno also awakens to a new power… Asta and Yuno, who both aspire to be the future Wizard King, pull off an impressive attack in front of the first Wizard King!

The Magic Knight Squad Captains decide to have a meeting about the problem with the devils that ended up involving the whole Clover Kingdom. Asta and the others who were in the Heart Kingdom were also summoned and they disclose the information they gathered in front of Julius, Damnatio, and the Captains. After hearing what Asta and the others had to report, Julius tells everyone what they need to do in order to deal with the devil Megicula.

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 Spade Kingdom successfully takes over the Diamond Kingdom and then sets their sights on the Clover Kingdom and Heart Kingdom. The Spade Kingdom troops get through the strong magic region using a mobile fortress which sucks up the mana of the Spade Kingdom citizens who were taken by force. But then Asta, who had finished his training with the Spirit Guardians, comes to the rescue! Meanwhile, Luck and Leopold head to the Spade Kingdom in order to try to take over one of their bases.

Due to Nacht's spell, the Devil who has been granting Asta power since the beginning has appeared physically. To master his Devil powers, Asta must battle and defeat his Devil, and force him to submit. But Asta has other plans... Meanwhile, Yuno, Noelle, and the others grow stronger in order to take their revenge against the Dark Triad.