Jasmine would decorate her house as some witches cottage and give full size candy bars for the kids

Andres would probably not do anything significant for halloween but he would buy a big bag of candy to take to the library a give to the students the next day

When Balei’s kids were younger she would go trick o treating, but now they’re older she just hands out candy in her house decorated like a dragons den, bunch of gold coin all around with a giant inflatable dragon, she’d go all out!

Wily probably got talked into it as it being a good/fun experience by Mahra, who accompanied him. Later in life he'd probably go HAM on decorations using weird tech and holograms. Ironically some people would be more scared of him than of any of that.

Polly would LOVE Halloween and take the chance to dress up as some of her favorite musicians, and bring some real ghosts out to play. Definitely snuck out to trick or treat as a kid.

Spikemuth goes all out for Halloween, so of course Stephanie decorated and Dory probably went trick or treating as a kid. Labi decorates and tries going full “Dude who throws a party just to kill everyone” mode, or spooking people.

Avian has a Hydreigon sygna suit outfit he wears at suitable work events. Stahl thinks 'trick or treat' is dumb. Arryn is either having a romantic meal with her husband, doing Lawyer stuff or getting trashed in an underground pokemon battle or rave.

Ruth would (but because she wants to know what its all about)
Sadie would (bc its an excuse to dress like a lil ho and get free shit)

Mary pulls out all the stops when decorating the house during Halloween. Her house looking like a haunted mansion when she's done. She and Jin would definitely be taking the kids out trick or treating

No and No.

Elio's not into Halloween, really. So trick-or-treating or "decorating his house" (which is funny because he would always be absent around this time via his journey or business trips) wouldn't happen.

For a full explanation, here's a link that goes more in-depth with it:
(https://retrospring.net/@Izetarion/a/108993864259545169)

Estella stopped going trick or treating, but she'd love to dress up and decorate a house given the opportunity. She'd enjoy a costume party for sure.