Well, the 'reunion' trope is quite popular. Characters who were separated in their own universes get to meet in the linked universe, often leading to very emotional scenes. There's also the 'discovery of new powers' trope. As they interact in the linked universe, characters may find they have abilities they didn't know about before. And the 'team - up against a common enemy' trope, where characters who might not have worked together in their original universes join forces to fight a threat in the linked universe.
Ganondorf can be a very popular character as well. He is the classic antagonist in the Hyrule series. In linked universe fanfiction, he could be the mastermind behind the new threats that the Links have to face, or perhaps a more complex, redeemed version of himself that adds an interesting twist to the story.
A plot idea might involve the Links having to deal with a rift in the fabric of Hyrule that is causing strange crossovers between different regions and time periods. They would have to find a way to close the rift while also navigating the chaos of these new, merged landscapes.
First, decide which universes you want to link. Then, create a main character or a group of characters that will be the focus. For example, if you're linking a fantasy and a sci - fi universe, think about how a character from the fantasy world would react to advanced technology. Next, come up with a basic plot like they are on a quest to restore balance between the universes. Start writing simple scenes to get the story flowing.
Some MHA characters might be flattered. For example, Midoriya would probably be really excited and take it as a sign of how much he's inspired people. He might even look for positive lessons in the fanfiction to improve himself.
Yang would likely have a big reaction. If the fanfiction shows her in a cool fight scene, she'd be all for it and might even show it off to her friends. But if it portrays her in a negative or weak way, she'd be really annoyed.
Tina, as a strong - willed Auror, might initially be skeptical. She'd be worried about the accuracy of the fanfiction in terms of the real wizarding world she knows. But after some thought, she might realize it's just a bit of fun for the fans and start to see the charm in it. She could even start to correct some of the inaccuracies in a friendly way if she ever had the chance to interact with the fanfiction writers.
Some characters might be flattered. If they are depicted as heroes in the fanfiction, it would boost their egos. For instance, Oliver Queen might enjoy reading about himself as an even greater hero than he already is.
Percy would probably find it hilarious. He has a good sense of humor and would likely enjoy the wild and crazy scenarios fans come up with. He might even share the funnier ones with his friends at Camp Half - Blood.
Naruto, being the open - minded and adventurous type, would likely find it fun to read fanfiction about himself. He could be amused by the creative ideas, even if some are a bit far - fetched. He might even take some of the positive ideas and think about applying them in his real adventures. Rias, however, would approach it more skeptically. As a devil princess, she has a reputation to uphold. She would carefully analyze how the fanfiction portrays her, and if it goes against her values or the image she wants to project, she might be a bit offended. But if there are some good aspects, like new ways of handling her devil powers or relationships, she might consider them.