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.
One common theme is friendship. They often start as friends and then their relationship may grow deeper. Another theme is support. Izuku might support Fuyumi in her personal struggles, like dealing with her family's expectations. And Fuyumi could support Izuku in his hero journey.
One common theme is the crossover of two different universes. Since Izuku is from My Hero Academia and RWBY has its own unique world, exploring how they interact and collide is a big theme. Another is power growth. Izuku usually has his own set of powers and abilities, and in the RWBY world, he either adapts or combines his powers with the RWBY characters' abilities. Friendship is also a common theme. As Izuku meets the RWBY characters, they form bonds and go through adventures together, just like in their respective original stories.
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 interesting 'izuku gets expelled' fanfiction could be where he gets expelled due to false accusations of cheating. In this story, villains frame him to get rid of a potential threat. Another might be a story where his quirk goes out of control during a test and the school, in a panic, expels him. There could also be a fanfic where a jealous classmate sets him up to look bad and get expelled.
In some fanfictions, Izuku deals with being expelled by seeking alternative training methods. He might find a retired hero who is willing to train him privately. This way, he can continue to develop his skills and prove that he is worthy of being a hero.
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.