Ash and his friends, accompanied by a new character named Sheena, are sent back in time by Dialga to stop Arceus and prevent its rampage. They must travel to the past to uncover the truth about the betrayal and prevent the world from being destroyed. reveals that ancient humans, with whom Sheena's ancestors were associated, were given a portion of Arceus's power as the Jewel of Life but failed to return it when the time came. This betrayal angers Arceus, who awakens from a long slumber and threatens to destroy the world

To save the world, Ash, his friends, and Sheena must travel back in time with the help of Dialga. They need to find out what truly happened in the past and how to prevent the ancient betrayal

If they fail, Arceus will destroy existence, and the combined might of Dialga, Palkia, and Giratina may not be enough to stop it. The movie serves as the finale to the story arc, revealing the secrets of the previous two movies and culminating in a race against time to save the planet

Arceus and the Jewel of Life! the Legendary Arceus is at the center of the recent disruptions in the Pokémon World. First the epic battle that threatened to tear a hole in the space-time continuum took place between Dialga and Palkia. Then Giratina, the sole defender of the Reverse World, had to take action to protect the precarious balance of its home and the Pokémon World. Now, Michina Town is at the heart of the action. The town has a long history and checkered past in relation to the mighty Arceus-after Arceus granted the townspeople some of its power as the Jewel of Life, they betrayed the Pokémon!

Ash and his friends, accompanied by their new companion Sheena, travel in time with Dialga's help to right the mistakes of the town's ancestors before the world crumbles under the power of Arceus's rage. Will they be able to fix the mistakes of the past? What really happened in the past-did Sheena's ancestors truly betray Arceus?

Ash: Pikachu use thunderbolt to Arceus!!! Pikachu hit the thunderbolt to Arceus but nothing happened to Arceus

Dawn: what we will do now

Sheena: I don't know he is stronger than I thought

Brock: we have to save the earth!