Naruto in Ash's world

Naruto's adventure in the pokemon world. What if Naruto was dying? his life is in jeopardy, but Kurama has no time to heal him because Madara was coming. So, in order to save Naruto and himself, he used a lost jutsu from the Sage of Six path to send them both to a completely different world. Everything is fine and dandy, but why is Kurama so small? And why can he only say 'Vulpix'