It's probably in the necklace. At least that what I thought at first but now I have at least 3 ways I can think of. Either her evil self is in the necklace or the earing. Or you could have something to do with that time the dad attacked His. But the last one seems kind of a stretch. Hell idk but I hope we find out at some point.
i thought it was when satan attacked his and then put the demon energy thing in her?
Hmm, no, I think Satan was just doing that to keep the demon energy under control because in ch. 23 Satan mentions something about 'the day' Haki and His spent together when they were younger. And I feel like 'The day' was probably when Haki's evil energy was planted inside His.
Ohhhh
probably who knows there are so many chapters now I am surprised I remember as much as I do still. it must be because I like this manga so much.(▰˘◡˘▰)
Aw man, im guessing that Haki's "evil self" was sealed inside of His when they were kids which is why His is so "weak".