Battling the Beast Within!
While training on Melemele Island, Ash once again encounters the Island Guardian Tapu Koko. Challenging it to a battle, its attacks clash with Pikachu's and create an Ultra Wormhole that drags Ash into a mysterious desolate world, one which has been destroyed and left in ruins. They discover that this is the world of the mysterious Ultra Beast, Guzzlord. However, Guzzlord starts to attack them until a mysterious trainer and his Zeraora comes to their rescue...