In fanfiction, Harry Osborn as Black Spiderman might bring a new dynamic to the story. His background as a rich and sometimes troubled character in the original Spider - Man story can add layers. For example, he could use his wealth in ways that a regular Black Spiderman might not. His family history and the influence of his father could play a role in his actions as a superhero. Also, his relationships with villains could be different. Maybe he has a more personal vendetta against some of them because of his family's past. And his relationship with Mary Jane or Gwen Stacy could be completely different from what we expect in the normal Spider - Man story.
The Avengers could find out who Spiderman is in fanfiction when they encounter a piece of advanced technology that can unmask his secret. Or maybe there's a betrayal within the superhero group and someone spills the beans on Spiderman's identity.
The Avengers would be among the most affected. They had been fighting Thanos for so long, and suddenly he's gone in a snap by Spiderman. Their whole dynamic would change. They might not know how to function without that common enemy. Also, the people of the universe who had suffered under Thanos' rule would be affected. Their lives would suddenly be free from his tyranny, but they'd also be in a state of shock and confusion.
Well, obviously Merlin and Arthur are the main characters. Merlin is the one whose secret as a Dragonlord is revealed, and Arthur is the one who discovers this secret.
In many 'Batman Beyond' fanfictions where Dana finds out, it could be about her finding out Bruce Wayne is Batman. Maybe she stumbles upon some evidence in the Batcave or notices some similarities in Terry's behavior to Bruce. For example, she might notice Terry's fighting style is similar to what she's heard about Batman's. It could also be that she discovers some secret technology related to Batman that leads her to the truth.
Maybe it's a mysterious figure from Merlin's past. Perhaps he had an encounter with a powerful magical being, and some kind of spell or pact led to the pregnancy. It could be a long - forgotten event that now resurfaces with this unexpected pregnancy.
There are many possibilities. It could be a character from Slytherin who has a long - standing grudge against Harry. They might be using abuse as a means to undermine Harry's confidence and disrupt his relationship in the romance aspect of the fanfiction. Another option could be a dark wizard in hiding who has a personal vendetta against Harry and sees abuse as a way to torment him without attracting too much attention from the wizarding community.