One common theme is the clash between the normal world of iCarly and the supernatural world of vampires. For example, in many stories, Carly and her friends have to balance their regular school and web - show life with the threat of vampires.
A lot of these fanfictions also deal with the idea of Freddie being an outcast because of his vampirism. He has to deal with the prejudices of the human world in the iCarly universe. And sometimes, there's a theme of him trying to find a cure or come to terms with his condition. It often adds an interesting layer of drama and conflict to the story, which makes it more engaging for readers.
Friendship is a very common theme. Since both shows have groups of friends, fanfictions often explore how the characters from icarly and victorious would interact as friends. For example, they might go on a road trip together.
One common theme is the development of their relationship from friends to something more. Since in the show there were moments of tension between them, fanfiction often expands on that.
Often, there's the theme of unexpectedness. In the show, their relationship is more of a tomboy - girly girl friendship. So in the fanfictions, when they kiss, it might be about how this sudden event shakes up their relationship and the people around them. It can also involve themes of confusion as they figure out their new feelings.
Well, there could be a theme of growth. Fans might write about how Mary and Freddie grow as individuals. They could start out as shy or unsure characters and then develop into more confident ones through their experiences together. Also, the theme of community could be present. They might be involved in something that benefits their community, like a fundraiser or a local event, and their relationship is strengthened through these shared experiences.
One common theme is the struggle with identity. Harry, being a vampire, has to deal with a new side of himself that he may not fully understand at first. For example, in many fics, he has to figure out how to balance his wizard self with his vampire instincts.
One common theme is the struggle between humanity and vampirism. When Ash is involved, it often shows his fight to keep his humanity intact even in the face of vampiric allure.
The theme of the outcast is also prevalent. Despite her power and allure, the vampire seductress is often an outcast in both the human and vampire worlds. Humans fear her, and vampires might be jealous of her power or see her as a threat. This sense of not belonging adds depth to her character and is often explored in different ways in fanfictions. For instance, she might try to find a place where she can be herself, or she might use her outcast status to her advantage by creating her own rules and living on the fringes of society.
Another theme is love and relationships. Since he's a vampire, his relationships with other characters, whether it's romantic or platonic, are often complicated. There might be a love interest who has to come to terms with Todoroki being a vampire, like in 'Todoroki's Vampire Love Affair' where the female lead has to navigate her feelings while also dealing with the danger that comes with Todoroki's vampirism.
A sense of otherworldliness is another theme. Vampire hypnosis fanfiction often plays on the idea that the vampire's world is different from the human world, and the hypnosis is a bridge between the two. In stories like 'The Otherworldly Hypnosis of Vampires', the hypnosis not only affects the human's mind but also gives them glimpses into the vampire's strange and alluring world, full of different rules, powers, and social hierarchies.