Responses
It actually is Elsa from the future and you can check it out in chapter 61 where she revealed her face which is Elsa if she was a adult and if Yvonne had died that would be what she look like but since Yvonne changed the past she probably might cease to exist
I thought I commented this weeks before, but I guess it didn't go through or it might have gotten deleted?
Anyway, I used to think the witch lady with the hood covering her head was Elsa from the future, but now I think it might be Olivia. Olivia has horns because she's half demon. Maybe the horns are what the witch lady is hiding under her hood.