Once reaching to the Demon Kings castle which would've been a long walk from the gate to the doorway itself. Its door towered over the guests. From the size comparison, this door would've assumed to be made to allow creatures like Tag inside if they were still alive. And invited to this party.
The doors opened, inside the light brightly shown through the dark, which almost blinded everyone due to their eyes being adjusted to the darkness. Once their eyes adjusted yet again, they would see a massive hallway with fire lit torches. A red carpet, and a staircase leading through at the end to yet another door. Above them would be gargoyles and other demonic decorations and statues around them. Along with stone rafters which surrounded both sides of this hallway as a second a floor to other rooms could be seen. Besides the torches that were similar to those that were outside and guided the guests to the castle doors. There were also chandliers above hanging off the roof. About 3 to be exact as they lead to the stairway across down the hallway they were entering. Their footsteps echoed as they walked down such a hallway and considering there were many guests here. Let's say it was quiet loud.
Heading up the stairway to the door, they would see what looked like a tall man in a butlers outfit, Wearing an Peacock mask. He stood at attention ready to serve the guests or at least until they approached. He spoke as he bowed to the guests.
Peacock: Welcome, Honoured guests. I am pleased to see that you all could make it to the Demon Kings Masquerade Ball! The Party shall started soon, I would be most delighted if you all could follow me through this door to the main ballroom, Here you will wait until the rules of the party shall be announced and eat on the delicious finger food our chefs have graciously provided for us!
They say, as he turns around and pushes the massive bronze and demonic decorated doors open revealing the inside of the Main Ballroom.
As everyone went inside this massive room. They would see ice sculptures of angels and demons alike, paintings of what they assume is the Demon King, Would show what the viewer depicts to be the Devil of their world wearing a crown and having a wine glass in one hand, and a skull in another sitting on his throne in the paintings.
Lastly, there was an empty throne at the far end of the room, with curtains and further demonic gargoyles and architecture behind said throne. Behind the curtains and enough to be seen by all who look, is a painting of what depicts the gods of this world in it. The Dragon, The Wolf, The Owl, The Giant, and of course. The Demon.
Music is echoing through the Main Ballroom as everyone is settling in waiting around for the Demon Kings game to start later.
The would-be butler will speak to the guests before he goes to do something else to prepare things.
Peacock: You may go eat the food as you wish while you all wait for the Demon Kings game to start. However, some rules. You may not take off your masks or you will be asked to leave and may not allowed back onto the Demon Kings Island. And secondly, if you wish to consume anything. All of your masks have a compartment at the mouth piece so you all can use that to eat, drink or if you are hyperventilating for ANY reason, can use it for some extra oxygen. It does get pretty thin up here if you're not used to it.
The Peacock butler would look at his wrist for his watch.
Peacock: Now, I must be going. More waiters shall serve more food, as shall I. The game will start within one hour. Now please, Enjoy yourselves.
He bows at the guests before taking his leave.
(OH forgot to mention!)
As soon as the guests went through the door. ANY distinguishing features that the group had were suddenly gone and they felt their masks being forced onto their heads.