Any interest in cutting off only the face? It's a pretty rare concept, pixiv tag for reference:
pixiv.net/tags/コロナル面切断

(attached is also a random example from said pixiv tag)

Was reminded of this concept when reviewing my idea from >4282 and >4283 and couldn't really think of a good way to make my idea work with this "cut off face" idea since anime character faces from a given series tend to look way too similar to each-other, and having some of the hair cut off as well like in the photo would result in mis-matched hair if you tried to swap with someone different thereby making it illogical that anyone could mistakely "assign" their face to the wrong head.