There could be lovers who are forced to meet secretly in the dark due to some family or social restrictions.
Perhaps it's two spies who meet in the dark to exchange information without being detected. Another possibility is that it's a group of rebels planning something against an oppressive regime and they choose to meet in the dark for secrecy.
In this fanfiction, Spider - Man is surely a main character. For the Oast side, it might be a group of characters. Maybe there's a leader - type character from the Oast who first encounters Spider - Man. And there could also be some sidekick - like characters who help or hinder Spider - Man's journey in the Oast world. They could have unique powers or personalities that contrast or complement Spider - Man's own.
The teachers of the major subjects are bound to be present. Snape, as the Potions master, would be there. His presence would add an air of mystery and his sharp intellect would be useful in any discussions. Flitwick, the Charms teacher, would also be important. He could offer his insights on how to make the students' learning experience more magical and engaging through charms.
Sirzechs Lucifer is likely to be present as he is a very important figure in the devil world. Azazel might also be there, especially if the meeting involves matters related to relations with other factions. And of course, the high - ranking devils from different noble families would be there.
The protagonist is a young man who is at odds with the expectations of his family and society. He is in a difficult situation regarding his personal desires and what is expected of him.
I don't know as I haven't read the story, so I can't tell who the main characters are.
The main characters are likely to be the ones from the original Twilight series, like Bella, Edward, and Jacob. Since it's a fanfic set in the Twilight universe, these are the central figures that fans would expect to see. However, there could also be some new characters introduced to add more complexity to the 'dark paradise' concept.
Naruto would likely still be one of the main characters, but with a much darker and more powerful version of himself. Sasuke could also be a main character, perhaps with his own brand of godlike power that rivals Naruto's. And there might be new, original characters created specifically for this fanfiction that have some connection to these dark godlike powers.
It's possible that some of the main characters from the previous story related to the dark troopers will return. They could be the ones who have had prior experience dealing with these menacing forces.
There could be diplomats from both China and Russia as main characters. They would be the ones representing their respective countries in the meetings and interactions related to the polar bear plot.
Obviously, Harry Potter himself would be the central character. Then, Voldemort would be a major figure as he is the main representative of the Dark Side. Bellatrix Lestrange could also play an important role as she is one of Voldemort's most loyal followers. She might be the one to initially tempt Harry or guide him into the ways of the Dark Side.