Whatever they do, for the final fight Ash must have a team composed of his flagship Pokemon of each region, normally they are his strongest Pokemon, not just the current team.
Pikachu
Charizard
Sceptile
Infernape
Greninja
Lucario
Also, a small wish from me would be that they use the same Ash Greninja transformation scenes as well as the theme.
Pikachu
Charizard
Sceptile
Infernape
Greninja
Lucario
Also, a small wish from me would be that they use the same Ash Greninja transformation scenes as well as the theme.