Misty did not come. She's not British and doesn't like stealing other people's holidays.
I think that Emma let Henry come on his own, but he had to be back by a specific time. Probably not the best party to let him go all alone, eh?
Snow White did show up, because she's down to mingle with the Displaced. Especially since she'd like your votes! Get someone with the Displaced's voice on the council! But she didn't actually talk politics. She chatted and brought the kids with her. They were little rugrats, probably running around and flying and other crazy shapeshifting things.
Clarke may or may not have come, depends on Bellamy.
Ahsoka went and twisted Luke's arm into coming. She probably tried to get Anakin to go too.
Aphra went. Per conversation with Jen, Aphra would have flirted with Alucard.
RICK WENT. Look it's a party and there's free booze. And then murder later.
Anya didn't go. She was trying to finish up some essays for class this week. Liv didn't go because she was at work.
Nikolai and Buffy came together. Look, bonfires and slaughter are romantic.