In a country called “Diamond Domain” lies the powerful Heart Diamond, which has served as the kingdom’s source of energy and maintained the Ore Country for centuries. Many Carbink live in Diamond Domain, including their princess – the Jewel Pokémon, Diancie, who created the Heart Diamond. Diancie no longer has the power to control the Heart Diamond and her country is falling into chaos as a result. One day, Diancie meets with Ash and his friends and asks them to go on a journey to find the Life Pokémon, Xerneas, in order to restore the Heart Diamond. Standing in their way is the Pokémon of Destruction, Yveltal, who once stole all of the life in the Kalos Region. During their journey they are attacked by Team Rocket, as well as the jewel thieves Marilyn Flame and Ninja Riot. They are aided by Millis Steel and her father Argus, travelers who also encounter the Cocoon of Destruction.

The story of The Empire of Corpses takes place in 19th century Europe, and revolves around John Watson. He is scouted by the government to become a secret agent- However, Watson lives in a world where “Frankensteins”- human corpses that are re-purposed with a false soul in order to use them as laborers- are used to improve industrial development.

All Might and Deku accept an invitation to go abroad to a floating and mobile manmade city, called ‘I Island’, where they research quirks as well as hero supplemental items at the special ‘I Expo’ convention that is currently being held on the island. During that time, suddenly, despite an iron wall of security surrounding the island, the system is breached by a villain, and the only ones able to stop him are the students of Class 1-A.