After Ash comes back home from Kalos he gets a vision or he saw the future events from Arceus view about the betrayal Ash went to Oaks lab where there he gets the nanodex and some of his Pokémon agreed with the traitors and only four Pokémon stayed with him(Pikachu, Charizard,sceptile and Greninja) has he disappeared to train he will have all the legendary Pokémon from Kanto to kalos has he trains he gains two new Pokémon and after 7 years the champions tournament will happen and are hero will compete with all the legendary Pokémon by his side what will happen.