Pokemon Movie 18: Ring no Choumajin Hoopa

Long ago, Hoopa used its rings to summon legendary Pokémon and prove its overwhelming strength, until a traveler sealed away the dangerous power that fed its arrogance. A century later, Hoopa lives in a smaller, harmless form near Dahara City, where Ash and his friends quickly become caught up in its playful use of dimensional rings.

When the sealed power is released, it takes shape as a furious shadow that wants to reclaim Hoopa and its old strength. Legendary Pokémon are pulled through ring after ring as the conflict escalates into a clash capable of destroying the city. Ash must help Hoopa confront the part of itself it once lost control of before the battle between legends tears the world around them apart.