I'm not sure specifically as it could vary greatly. It might be about a thrilling adventure where characters are trying to escape some sort of danger during the night.
Joey Graceffa is a very popular character to include. His presence can add a lot of drama and leadership to the story. Also, Colleen Ballinger would be a great addition as she can bring her comedic yet strong - willed personality. Another one could be Shane Dawson, who has a very unique and often dark sense of humor that would fit well in the spooky 'escape the night' world.
Perhaps a group of misfits, who are all outcasts in their normal lives, are brought together in 'escape the night'. They initially don't get along but as they face the various deadly challenges, they learn to work together. They find out that there is a traitor among them, planted by the 'evil force' behind the 'escape the night' ordeal. They have to figure out who the traitor is while also trying to escape.
The title 'The Night Children An Escape from Furnace' gives the impression that there are children involved in a rather harrowing situation. The 'night' might add an element of secrecy or danger. 'Furnace' could be a metaphor for a prison - like place, perhaps a place where they are being held against their will. And the 'escape' part is about their attempt to break free from this situation. It could be a story full of adventure, with the children facing various obstacles during their escape.
If you're doing a crossover with 'Marvel', characters like Spider - Man would be great. His agility and quick thinking could help in the 'escape the night' scenarios. Also, Iron Man with his technology could provide some useful gadgets. In a crossover with 'DC', Batman would be a good addition. His detective skills and combat abilities would be very useful. Another option could be Wonder Woman, with her strength and courage.
One idea could be to cross it with a fantasy world like 'Game of Thrones'. The characters from 'escape the night' could find themselves in the middle of the power struggles in Westeros. Another is to crossover with 'Stranger Things'. They might have to deal with the Upside Down while also facing the challenges from their own world. Maybe also a crossover with 'The Hunger Games', where they are forced to participate in the deadly games in a new and unfamiliar arena.
Sakura would probably be very hurt. She has deep feelings for Sasuke, and if she found out it was just a ploy to escape, she'd be heartbroken. She might also be angry at being used in such a way.
The village would likely be in chaos. Naruto, despite being an outcast in some ways, was still an important part of Konoha. The Hokage and the ninja leaders would probably send out search parties immediately to find him.