From the look of previous chapter umi made her dad dissappear at will from what i see maybe that’s her power. So if she wishes that herself disappear the power will activate on herself maybe
I like how the character are unlikable time to time. It makes them feels not perfect and more human-like. Plus in this case it seems like the author is intentionally making them this way too
Since both webcomic and serialization are connected together in a way that if you haven’t read webcomic first some of the flashback wouldn’t make much sense, in my opinion i think it would be better to merge the 2 to make it easier to understand