Another fanfic could focus on the training methods in both universes. Shigeo could learn some new ways to control his powers from the teachers at U.A. High School. And in return, he could show the students there how to deal with internal mental struggles. This could create a great story of cross - cultural learning between the two worlds.
One idea could be a crossover where Mob and Midoriya meet. Mob's psychic powers and Midoriya's One For All could lead to some really interesting team - up scenarios. Maybe they have to face a villain who can manipulate emotions and they combine their powers to defeat the villain.
A great crossover often involves a good balance of the powers from both series. For example, when Reigen from Mob Psycho 100 somehow gets involved in a My Hero Academia battle. His con - artist skills could be used in a really unexpected way, like tricking the villains into believing he has a powerful quirk.
In a fanfiction crossover, it could be that the villains from both universes team up. The Claw organization from Mob Psycho 100 and the League of Villains from My Hero Academia might form an alliance. This would force the heroes from both series, like Shigeo Kageyama and Izuku Midoriya, to work together. They'd have to learn from each other's strengths and weaknesses in order to defeat this powerful new threat.
Reigen Arataka from Mob Psycho 100 is a bit of a con artist, but also has a good heart. If he were to meet characters like Katsuki Bakugo, it would be an interesting mix. Bakugo's explosive personality might be challenged by Reigen's ability to talk his way out of situations. Reigen might try to use his 'psychic' skills (even though they're mostly fake) to impress Bakugo or get on his good side, which would lead to some comical moments.
I really like the idea of Shigeo 'Mob' Kageyama and Izuku Midoriya interacting. Izuku is so determined to be a hero despite being initially quirkless, and Mob has such strong psychic powers but is often so reserved. They could learn a lot from each other. Izuku could teach Mob about the importance of having a clear goal in using his powers for good, while Mob could show Izuku some of the more spiritual and internal aspects of power control.
I really liked 'A Different Kind of Hero'. In this fanfic, it delves deep into how the concepts of power and heroism from both series interact. The author does a great job of bringing together the characters from both shows. For example, Shigeo Kageyama's calm and collected nature contrasts well with some of the more brash characters in My Hero Academia, creating some really engaging character dynamics.
The character interactions are a big draw. Characters from both shows have such distinct personalities. You could have Deku from My Hero Academia meeting Mob and learning about his way of handling his power. Their different outlooks on heroism and self - worth would make for some really interesting conversations and character development.
Training scenarios are often explored in fanfiction. How would the characters train in a combined setting? There are also fanfics that deal with the idea of redemption for villains. In the context of these two series, it could be interesting to see how a villain from one might be redeemed in the other's world. Additionally, the exploration of different cultures within the two series can be a theme, as both have unique settings and character backgrounds.
In My Hero Academia fanfiction, a common theme is character development, like how Midoriya grows in power and as a person. Another is exploring different quirk combinations. For Mob Psycho 100, themes often revolve around Mob's struggle with his psychic powers and his relationships. Friendship is also a big theme in both, showing how characters support each other through tough times.
A crossover might also involve Reigen from Mob Psycho 100 trying to start a business in the My Hero Academia world. He could claim to be a quirk - enhancer trainer or something similar. It would be hilarious to see him interact with heroes like All Might or Endeavor, trying to convince them that his 'methods' are legitimate while they're just confused by his over - the - top personality.
Well, you could write a fanfiction about Mob's family. For example, how his older brother's life was affected by having a psychic younger brother. Maybe there were times when he was jealous or proud in ways that haven't been explored much in the original. Or a story where Mob uses his powers to help people in a more global sense, like solving international disputes with his psychic abilities, which would be a very different take on the usual small - scale problems he faces in the anime.