An article inside Eyes and Ears (a Cast Membe magazine) shows a list of some of the villains that will be at the party (they didn't make any distiction between meeting and greeting or just dancing or on stage)
Hades, Pain, Panic, Megara (she's not a villain in my opinion but excited to be able to see her up close) Maleficent, Captain Hook, Dr. Facilier, Evil Queen, Big Bad Wolf, Man in the Bowler Hat (Adult Goob from Meet the Robinsons) and more.
DHS Time Guides are out for next week and here's what it says:
Unleash the Villains!
This Friday the 13th, experience Limited Time Magic at its most villainous
when Hades himself and 13 Disney baddies invade Disneys Hollywood
Studios with a devious dance party, themed snacks and fiendish fireworks!
And be sure to pick up a special Unleash the Villains t-shirt at Villains in
Vogue on Sunset Boulevard. #LimitedTimeMagic
Dance Party at Sorcerer Hat...........................8:00pm1:00am
Meet the Villains Echo Lake... 8:30pm10:30pm & 11:30pm12:30am
Villainy in the Sky at Sorcerer Hat.............................11:00pm