This is making me think of Bleach so much especially with Bankais and Shikais even. "Zoan-pakutous" lmfao.
I think Oda mentioned everything in the world has its own soul, some kind of sentience when Zoro had the Breath of All Things moment vs Daz Bones or something like that? That always made me wonder on the potential and possibilities of that.
We recently learned cursed swords are "not cursed" but just have their own wills, their own sentience and thus personalities and have to be tamed and understood like wild beasts with their unique dispositions or w/e. Another Luffy and Zoro parallel going on right here too then?
yeah, animals in one piece do acquire an independent willpower through watching and mimicking humans like the humandrills at mihawk's island, and the starfish kamie's pet.
zunisha too has a will of it's own, inuarashi was surprised to learn that which suggests that it's a rare case.
this business with luffy's fruit is tricky, because first of all it's a god with specific purpose, and there's too many requirement:
-male user
-specific space-time frame
-death
-...
it's not like swords that only requires a certain level of strength in order to be tamed.