>>32041452>Yajima wanted to make the bond between Satoshi and Gekkouga a major part of the story, but felt it would be difficult to do so if it had to remain a Gekkouga, so he went to Game Freak, and they came up with the idea of a synchro transformation. It was put in Sun/Moon afterwards, but was created during this discussion between anime staff and GF.The form wasn't his idea, it was Game Freak's.
He didn't ask for anything in particular, just something to give Greninja more importance (and a way for it to be able to fight Megas), and Game Freak came up with the Ash-Greninja form.
