One common theme could be redemption. Izuku may be expelled unjustly, and the story could focus on his journey to prove himself and regain his place in the hero world.
One possible aspect to analyze in 'izuku expelled fanfiction' could be the character development. Since Izuku is expelled, it would be interesting to see how he copes with this setback and grows from it. Maybe he discovers new powers or forms new alliances outside the school system.
A major theme is the struggle against overwhelming expectations. Izuku has high expectations from himself and others in the world of the story. When he fails to meet them, it leads to his depression. Also, the theme of lost hope is common. He might lose faith in his dreams and his ability to become a hero. In some fanfictions, his depression is also linked to past traumas, like being bullied for not having a quirk initially.
One common theme is the struggle with identity. Izuku has to come to terms with being a vampire in a world where he was previously a normal human. Another theme is isolation, as he may feel different from his friends and classmates. And often there's a theme of power, exploring how his vampiric powers change his role in the hero - related events.
One common theme is Izuku's growth and development. Since he's older, he might have more advanced skills and a deeper understanding of his quirk. Another theme could be his relationships, perhaps more complex romantic relationships or stronger friendships with his peers.
Another theme is mentorship. Sometimes, female characters take on a mentorship role for Izuku. They might have different skills or knowledge that they impart to him, like unique fighting techniques or strategies.
One common theme is redemption. Draco often has to redeem himself from his past actions as a Slytherin. For example, if he tries to help Hermione who has been expelled or is at risk of being arrested. Another theme is forbidden love. Their houses and past enmity make their relationship something that is not easily accepted in the wizarding world.
One common theme is the development of their relationship from rivals to something more. Given their original dynamic in the source material, fanfictions often explore how they can overcome their differences. For example, in many stories, they start to understand each other's motives and goals better.
One common theme is the 'opposites attract' idea. Since Mina is more outgoing and Izuku is initially shy, this contrast makes for an interesting dynamic in the stories.
One common theme is friendship. They often start as classmates and gradually become close friends, relying on each other. For example, in many fics, they help each other deal with family issues like Todoroki's complex family situation and Izuku's insecurities.
A lot of these fanfictions also deal with the idea of romance. Given the popularity of shipping in the My Hero Academia fandom, it's no surprise that many stories focus on romantic relationships between Izuku and the 1a girls. Some might explore how they handle jealousy when other characters are involved in Izuku's life. And there are often themes related to self - discovery too. As the characters interact more closely with Izuku, they might learn more about themselves, their feelings, and their own potential as heroes.