Probably still Hinawa, I think?  I mean, nobody’s personalities got switched around with their genders, and the loss of Hinawa’s specific personality, I think, is part of the reason that things in Mother 3 turned out the way they did.

(Not that nothing would have happened if Flint had died instead, but I doubt Hinawa would have gone on a rampage of any sort, which means she wouldn’t be in jail overnight and during the funeral and be unable to comfort the twins, and then she might have been able to dissuade Claus - or, in this case, Colette, from doing something stupid, etc.)