A few days after the ball, everyone is rushed away to their rooms. The lock clicks shut behind them. After a few moments, a lime green mist fades into the room. After taking a few breaths, every kidnapped person falls asleep. That's when the villains game happens. The villains Take control of their dreams/nightmares. They control what happens. The kidnapped just have to figure out how to escape early, or survive the whole night.

Certain vks who are devoted to the villains, like Wynter, would help the villains control dreams.

Good luck. . .