Another theme might be his relationships. Maybe in these bashing fanfictions, his relationships with the female characters are misconstrued or made to seem one - sided in a negative way. For example, his bond with Moka could be portrayed as him being clingy or unworthy. Also, his attempts to fit into the monster school could be shown as him being incompetent rather than the plucky underdog he is in the original story.
One common theme is the development of Tsukune's vampire powers. Writers often explore how he copes with his new abilities and how they change his relationships with the other characters.
I'm not really sure of specific 'rosario vampire tsukune bashing fanfiction' titles off - hand. You could try searching on popular fanfiction websites like Fanfiction.net or Archive of Our Own and use those keywords in the search bar.
Another theme could be the discovery of self. Through their relationship, both Mizore and Tsukune learn more about themselves. Mizore might become more in touch with her softer side, and Tsukune might discover new strengths within himself while being with her.
One common theme is power struggles. Since Alucard is a very powerful vampire and Tsukune is a human - turned - vampire with his own unique abilities, fanfictions often explore how they interact in terms of power. For example, they might have to team up against a greater threat while also dealing with their own differences in power levels.
One common theme is friendship development. Since Tsukune is the main male character and Yukari is an important female character, many fanfictions explore how their friendship grows over time, especially considering their different personalities. Yukari is often portrayed as a bit mischievous, and Tsukune is more of the normal guy in a strange world, so their interactions can be really interesting to read about.
A lot of Tsukune x Mizore fanfictions play with the idea of forbidden love. Since Tsukune is a human in a world full of monsters, and Mizore is a monster, their relationship is not without challenges. Also, themes of loyalty and sacrifice are quite common. They might have to sacrifice something for the sake of their relationship or their friends. Some fanfictions also explore the theme of self - discovery, as both characters grow and change through their relationship.
There are also fanfictions that focus on the internal struggles of the characters. Kurumu's nature as a succubus might lead to her having insecurities about her relationship with Tsukune, fearing that her instincts could harm him. Tsukune, on the other hand, may struggle with his own identity as a human in a world full of yokai. These internal conflicts add depth to the characters and the fanfiction.
One main theme could be power. With Tsukune as a god, power dynamics are likely to be a big focus. Another might be transformation, not just in terms of Tsukune's new status but also how it affects the other characters around him.
First, know the characters well. Tsukune is a complex character with his own growth arc. Make sure to stay true to his personality. Also, understand the world of Rosario Vampire, like the different monster species and their cultures. Then, come up with an interesting plot. It could be a new adventure for Tsukune or a different take on his relationships.
One theme that frequently appears is identity. Tsukune has to reconcile his human self with his new monster self. It's not just about the physical change but also how he views himself. Also, the theme of protection often comes up. His monster form might make him better able to protect those he cares about, like his friends at the academy.