Another character often paired with Mount Lady is All Might. Maybe in a 'what - if' scenario where they train together, or she has to save him at some point. Their interactions could explore different power dynamics within the My Hero Academia universe.
Hermione Granger and Momo Yaoyorozu are also commonly paired. Both are extremely intelligent characters. In fanfiction, they might collaborate on some amazing projects, using Hermione's knowledge of magic and Momo's quirk to create something that benefits both worlds. They could also bond over their love for learning and their determination to be the best in their respective fields.
Ochaco Uraraka is often a popular choice. Her cute and friendly personality makes her a likely candidate to be part of a harem. Tsuyu Asui is also common, with her unique frog - like quirk and calm demeanor. Momo Yaoyorozu is frequently paired as well, given her intelligence and leadership qualities. Additionally, Mina Ashido with her fun - loving nature can also be found in many harem - related fanfictions.
One interesting storyline could be Mount Lady facing a new type of villain that can manipulate the earth in ways she's never encountered. This forces her to use her quirk in creative ways to overcome the threat.
Bakugo is often paired with Izuku. Their complex relationship can add a lot of drama to the detective story. Bakugo might be reluctantly helping Izuku or even be a suspect in the case Izuku is investigating.
Uraraka is also common. Her friendship with Deku, and perhaps a budding romance in some fanfictions, can add an interesting dynamic. She could be involved in missions with Deku or be there to support him during difficult times.
Definitely Ochaco Uraraka. She has feelings for Deku in the canon story, so she's a natural fit. Then there's Jiro. Her music - based quirk and her cool attitude can be really appealing in a harem setting. Toru Hagakure, the invisible girl, also shows up a lot. Her unique quirk and her kind heart make her an interesting addition to the harem. And Nejire Hado from U.A.'s Big Three also sometimes appears in Deku harem fanfictions, adding a bit of an upperclassman allure.
One common theme is her growth as a hero. Fanfictions often explore how she becomes more powerful and skilled. Another theme is her relationships, whether it's with other heroes or civilians. For example, her interactions with the media are often explored.
Deku is often a popular character in 'My Hero Academia Flame On' fanfiction. His original quirklessness and then his development into a powerful hero make him a great candidate for stories involving new or enhanced flame - based quirks. Bakugo is also popular as his explosive quirk can be easily related to the idea of flames. Fans like to write about him further exploring the power of his explosions in relation to the 'Flame On' concept.
One of the most memorable characters could be the fan - made villain with a really unique quirk. Maybe they have the ability to manipulate time in a small area, which makes them extremely difficult to defeat. Their backstory of how they got their quirk and why they turned to villainy is also very engaging.
Midoriya Izuku is often a popular character. In godlike fanfictions, he might be given even more powerful versions of his One For All quirk, or he could develop new abilities that make him even more of a force to be reckoned with. Writers love to explore his growth and how he would handle extreme power.