Well, one possible fanfic could be about Android 18 and Raditz teaming up against a common enemy. Maybe they initially start off as reluctant allies, but as they fight side by side, they begin to respect each other's strength.
Perhaps in the fanfic, Android 18 uses her combat skills to train Raditz. Since she has a lot of fighting experience, she could help Raditz improve his techniques. This could lead to an interesting dynamic where Raditz becomes more powerful under her guidance.
Common themes in 'Dragon Ball Z Raditz x Bulma fanfic' often include the clash of their different worlds. Raditz comes from a warrior - based Saiyan culture, and Bulma from a more technologically advanced Earth culture. So there could be a theme of how they learn from each other. Also, themes of love against all odds can be present, as their relationship would be quite unorthodox in the context of the original Dragon Ball Z story.
If Raditz survived in fanfiction, he would likely have a complex relationship with Goku. He might start to see the value in Goku's way of life. Goku could try to reform him, and Raditz could slowly become a more positive force in the Dragon Ball Z universe.
Yes, there are quite a few. You can start by looking on fanfic platforms like FanFiction.net or Archive of Our Own. Some fanfics might focus on alternate universes where Raditz has a different relationship with Bulma and Trunks, perhaps a more friendly or even a mentorship - like relationship. However, the quality can vary greatly, so it's important to read reviews or summaries before diving in.
If Raditz turned good, it would have added a whole new dynamic to the Dragon Ball Z universe. He could have become a valuable ally, sharing his knowledge and skills to help the heroes.
There could be some really creative 'Dragon Ball Z Raditz x Bulma fanfic' out there. However, I haven't come across one myself lately. In general, in such a fanfic, the author might play around with the different personalities of Raditz and Bulma. Raditz is a Saiyan with a more aggressive nature, while Bulma is smart and resourceful. The story could involve how they interact in different scenarios, like if Raditz somehow survives longer in the story and forms a relationship with Bulma.
One common theme is family dynamics. Since Trunks has a family connection with Bulma, and Raditz being an outsider, the fanfics might explore how Raditz fits into or affects that family unit. Another theme could be redemption. Raditz was initially a villain, so fanfics could show him redeeming himself in the eyes of Bulma and Trunks.
Perhaps the fanfic could be a time - travel story. Android 21 accidentally sends Goku back in time to a point where she was first created. Goku then tries to prevent her from becoming the villain she was meant to be. This would involve Goku having to deal with the scientists who created her and convincing them to take a different path in their research, all while trying to find his way back to his own time.
It could also be a fanfic centered around their friendship. Android 18 might initially be cold towards Bulma, but as time goes on, they start to bond. Bulma could introduce Android 18 to the joys of normal life, like shopping or going to the beach. And Android 18 could protect Bulma from threats that her scientific work sometimes attracts. In the end, they become inseparable friends, changing the way the other characters view Android 18.