Elizabeth is so down for this! She will need explanations on both Summerween and trick or treating (it wasn't really a Halloween custom until the '20s), and she's going to dress as one of her favourite book characters, Cosette from Les Misérables! She'd be especially excited about helping kids get more candy than getting it for her own sake, but if she comes across the Trickster she'll give him a piece of her mind for putting such a morbid price on something that would otherwise be so fun.

Arya will also need things explaining to her, but she will be thrilled about the whole thing and wish that all the events were like this. She's going to be dressed as Visenya Targaryen, a badass warrior queen from her own world. With the long blond hair and House Targaryen sigil, it's plausible she could be mistaken for a certain other Targaryen (if that's okay Kai). The only thing that will burst her bubble is if the Trickster kills one of her close CR - then she'll be entirely focused on trying to kill him in return, though of course she'll fail miserably there.