As Asta and the others were chasing the creature that lived in the cave beneath the Yultim Volcano Trail, they happened upon a dungeon. They were then ordered to explore the dungeon by the royal capital, so they split into groups and went in. They head in with Leopold and Vice Captain Randall, but those two end up running into the creature from earlier. They work together but cannot defeat the monster, which makes Leopold feel useless. At that moment, Leopold remembers the strange feeling he felt when he was fighting the elves, and...

The Black Bulls get a sudden visit from Mereleona and she drags them to the strong magic region of the Yultim Volcano. There, the Crimson Lion Kings, as well as their captain, Fuegoleon, and his younger brother Leopold, were waiting for them. Asta and Noelle remember the hot springs they had visited on their previous trip there. Finding new resolve, Magna, Luck, Charmy, Gordon, and Nero all decide to train in the fiery underground cave of the volcano!

Asta and Yuno are given permission to go home to Hage for a little while. Asta was being called a devil in the papers, but Father, Sister Lily, everyone at the church, as well as the people who even used to make fun of Asta and Yuno because they were orphans, welcomed them home with open arms. Asta and Yuno see that they had gone down the right path and all their hard work wasn’t for nothing, and then...

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 the others manage to meet with the queen of the Heart Kingdom, Loropechika, who had also been chosen by the water spirit, Undine. They are able to confirm that the devil’s curse that they spotted in the Heart Kingdom was originating from Loropechika herself and that the devil was in the Spade Kingdom. Meanwhile, Vanessa, Magna, and Luck went to investigate the Diamond Kingdom and find it in ruins after a single mage of the Spade Kingdom had annihilated them. In order to defeat this devil, Loropechika asks Asta and the others for their help...

Thanks to Gordon’s father, Asta and the others were able to find out that there might be clues surrounding the devils in the Heart Kingdom and manage to get permission to enter the kingdom due to the fact that Mimosa had gone there previously to study overbroad. Asta, Noelle, Finral, Mimosa and Nero head to the Heart Kingdom. Asta and the others initially enjoy their trip there, but something that Langris told Finral had been bugging Finral. Suddenly, Asta and the others are faced with a rather unexpected trial. Will Asta and the other Black Bulls be able to obtain information on the devils?!

In order to find out more about the forbidden curse, Asta, Gordon, Grey, and Gauche head to Gordon's house, since he comes from a family of famous curse mages. Once they get there, they can't help but show their wariness towards Gordon's family. But in the end, they end up finding out valuable information while they're there. Meanwhile, Noelle goes to talk to the Dorothy Unsworth, the Captain of the Coral Peacocks, after her brother tells her to talk to her to find out the truth behind their mother's death. Dorothy tells her the name of the devil who had killed her mother, and the same name is spoken by Gordon's grandmother. That devil's name is...

The Black Bulls were ordered by the Wizard King to investigate the devils. Yami takes Asta and Nero and goes to talk to Captain Charlotte of the Blue Rose Knights, since she has experience with forbidden magic and curses. But when they get there, Charlotte suddenly runs off somewhere and they’re all in shock. Charlotte had memories of while Charla took over her body and fears that Yami had found out her true feelings and she ended up panicking. But then, she makes a decision.

The Black Bulls return to where their base originally was. Henry has to return the Raging Bull back into their hideout, but apparently, that takes some time. Meanwhile, Yami tells the Black Bulls to go find the magical beasts that escaped from the hideout. They had run away when Rades and the others had attacked the hideout and had been wandering around the forest ever since. There was even a chance that they had returned to their feral states. Their fear comes true, as one Black Bull is attacked after another.

After using forbidden magic in the fight against the devil, Secré turns into a bird and ends up spending centuries all alone. During that time, she ends up meeting Asta, who ends up with Licht’s grimoire that has a different devil residing in it. Patry ends up reviving due to resurrection magic, and then he becomes the leader of the Eye of the Midnight Sun and vows to get revenge. This was all according to the devil’s plan and Secré uses her sealing magic to free Lumiere and Licht so they can finish off the devil once and for all along with Asta. The battle comes to an end, and Secré now begins her new life as a member of the Black Bulls.

Because she used forbidden magic, Nero survived for centuries. In the back of her mind, memories from long ago start to replay in her head. From when Nero was still called Secré and when Secré first met the most powerful and talented mage in the Clover Kingdom, Prince Lumiere. They become friends with Licht and the other elves, but due to the evil plans of a devil, the humans end up killing all of Licht’s comrades. Because of that, Licht ends up turning into a demon and Lumiere finds him in that state. What will he have to do to protect the ones he loves?

Asta, who has the power of the devil, and Secré who used forbidden magic and turned into Nero, were called before the Magical Parliament to be judged. Asta maintains his innocence, but Damnatio Kira will do everything he can to probe that Asta is guilty. In order to save Asta and Secré, Yami shows up with the Black Bulls and they cause a ruckus. While the Black Bulls cause trouble, a few others show up...

The battle involving the whole Clover Kingdom is finally over. But because of the battle, the kingdom was heavily damaged, so the Magic Knights were busy trying to repair everything. Meanwhile, someone rather unexpected shows up in front of Asta and the others and states three problems that will come up for the Clover Kingdom. Asta and the others are surprised, but just as they were told, someone showed up to try to judge Asta and his devil power.

The Shadow Palace begins to shatter, but Asta and the others manage to escape. Meanwhile, the elves continued to attack the kingdom because they still didn’t know the truth. Asta is the only one who can undo the resurrection, but it won’t be easy to save all of them at once. Patry then frees Vangeance, who’s sleeping inside him, so he can use his world tree magic and Licht can use his magic that connects him with all of the elves and Asta is able to undo the resurrection of all the elves at once. Finally, the long battle is coming to an end.

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!

To stop the devil from leaving the Shadow Palace Asta, Yuno, and Patry, who had just regained his senses, head to the top floor. Once they get there, they are greeted by the first Wizard King, Lumiere Silvamillion Clover and the one who serves him, Secré Swallowtail。Secré is the true form of the mysterious bird, Nero, and she is a mage that uses a rare magic called sealing magic. She uses her magic to break the seal on Licht, and they are able to witness the true leader of the elves, Licht, and his true powers. An epic battle begins so that Licht and Lumiere can get revenge against the devil.

The strange little black bird Nero, who kept following Asta around, suddenly appears before Finral, who had just finished fighting with his brother Langris, and demands that he take them to the Demon’s bones back in Hage Village. Finral is obviously startled that Nero’s suddenly speaking human words but obliges and takes Nero to the bones and witnesses an unbelievable sight. We will finally find out the true events that befell the elves 500 years ago! Meanwhile, back at the Shadow Palace, the devil’s eerie magic fills the room.

“When the owner of the four-leaf grimoire is filled with despair, the five-leaf clover grimoire will be born.” Patry is filled with despair after learning he had been manipulated by the devil all this time and turns into a dark elf. He then starts attacking Yuno and Asta, fueled by nothing but hatred and malice. Somehow, becoming a dark elf had made Patry even stronger, which gives Yuno and Asta an even harder time fighting him. Then Captain Nozel appears before them. Nozel happens to have the best magical attribute to fight against light magic, mercury magic.

Yuno manages to enter the Shadow Palace with his pendant and runs into Patry and the others. However, his pendant is immediately stolen. Now, all of the necessary magic stones have been collected and the elves’ wish was supposed to come true. However, an uninvited guest appears before them: A devil from another world. They find out everything that happened between the elves and humans were actually a part of his plan all along. Yuno can’t hide is astonishment at how powerful the devil is as he tries to fight it, and then Asta and Mimosa also arrive!

The Black Bulls fight off the elves as Asta and the captains head into the Shadow Palace. However, they start to feel cornered from being so run down from one battle after another. It was then that Yuno had finally arrived to save them, bringing other Magic Knights he found throughout the land with him. Yuno hears the situation from Charmy and decides to head into the Shadow Palace, too. However, the entrance was now closed. But then, his pendant starts to react in a strange way...