>>28595759I had the idea because I was thinking about the Hero Greninja from the ninja village. It was the fact that it, along with other Pokemon were the ones who saved the village.
There was no mention of a trainer, human partner, or anything of that kind. So it had to get that form some how if it was fighting independently.
So what if it was possible to hold that form indefinitely. That's when I thought of the final Greninja form was permanent AshGreninja.
Because not only that, during TF Greninja takes damage but Ash doesn't feel the pain. Maybe it's because of time constraints, but it could also be a sign to show that Greninja is becoming strong enough to control the AshGreninja power on its own.
Like Mega Evolution a Pokemon only becomes able to use it when a Trainer becomes its 2nd half to unlock that power.
But since AshGreninja while similar to Mega Evolution, is said to have latent abilities to achieve a power never seen before, being able to control and use the AshGreninja power on it's own would be said latent abilities.