My theory on the eyes is similar to yours. I will describe it briefly. First of all, this is my list of people with the eyes:
Mihawk
A couple of the special Seakings Shirahoshi controls
Cavendish
BM
Pudding
Luffy
Zunesha
In my eyes, BM, Luffy, Pudding and Cavendish point towards the idea that multiple wills is the cause of the eyes. It is possible that this is the will of a devil, but it is not entirely clear.
The fact that Cavendish does not have a devil fruit and still has this dynamic makes it think it is not devil fruit related.
Pudding has been shown to have somewhat of a split personality with Sanji, where she will be like "ALL YOUR FRIENDS WILL DIE...Sanji-san". Whenever she goes into her grim state, her eyes are weird.
Cavendish turns into Hakuba when he sleeps and not only is he stronger, his overall fighting style is different. I think this is further indication that multiple wills are present rather than just some kinda power up
BM gets the crazy eyes when she goes into her berserk mode, which I see as her losing herself and becoming a different person. The O-lin dynamic also points to the idea that BM is fundamentally 2 different people: A evil berserker and a protective, kind person.
Zunesha is under the influence of someone's will in a way that we don't fully understand. The eyes of Zunesha could be caused by the will that is making Zunesha walk.
Seaking: I have no idea
Mihawk: I have no idea. Inheriting the will of the world's strongest swordsman, and becoming that? Ehhh, maybe.
Luffy: Super clear here. When the a human zoan of a specific person is awakened, it is basically letting that person's will exist with your own. Luffy is clearly influenced by Nika in his awakened state, but he is still Luffy. In my eyes, Luffy's awakening gives the best evidence of multiple wills being tied to the fruit, since he has never had those eyes until his awakening.



would be such a Oda move












that is my explanation: mother carmel was who introduced the first giants into marines, if i am not wrong there is an actual panel of her explainin tho, it is pretty obvious for me i dunno what to explain keturin, try to elaborate why you aint see any conection on this



do you watch their facial expressions when they are saying i mean nami says that in funny way but big mom was damn serious about it. Wait for the episode to come then see it





Be sure to shy away from spoilers if you pick the anime
