Max Guevara came alone, dressed in a long red dress and fabulous heels. Her hair was up off her neck, with tendrils around her face, like this.
Kylo Ren arrived on Eliot's arm, dressed in all black with a splash of red. They've been together a year, and he's clearly more comfortable than he's been at previous events of this type.
Credence Barebone was incredibly uncertain about coming, but in the end he was convinced, so he came alone, or with Luna - sort of, he wore his green with Slytherin pride, and added a suit jacket to this ensemble.
Anakin Solo came with Nico di Angelo, although he was pretty quiet, and there is a very good chance that he left early. I suspect he wore a suit he'd worn before to one of the other events, he looked nice, but also obviously tired cause he's tired of losing his family. :(
Charlie Weasley #2 came with Steph (and I'm tired of finding men's wear sorry) and wore a nice suit, possibly a burgandy bowtie, as a nod to what she was wearing, and his whole suit likely has a bit of a casual edge to it - cause he doesn't usually do super super formal, but he looks sharp.
Poe Dameron arrived with Finn, and he was ecstatic about this fact. He was all smiles, and dressed pretty damn smart for the occasion, cause that's how he do.