One common theme could be adventure. Since it's set in an 'underground' setting, there might be elements of exploring the unknown, facing challenges and obstacles. Another theme might be the relationship between rex and the devilartemis characters, which could involve friendship, rivalry or even some form of cooperation.
Frieza might initially be shocked. He's used to being a feared and powerful being, and the idea of having a family is very foreign to him. So he could be in denial at first.
For Yamcha, you can focus on his growth from being a bit of a comical character to a more serious and respected fighter in the context of his relationship with Frieza. Maybe he learns from Frieza's cold and calculating nature how to better strategize in battles. For Frieza, his development could be about him learning to care for someone other than himself. He could start to see Yamcha as an equal, which is a huge shift from his usual superiority complex.
Well, I'm not that familiar with specific 'rex in the underground devilartemis fanfiction' stories. But you could try searching on popular fanfiction websites like Archive of Our Own. They usually have a wide variety of fanfictions and you might be able to find some good ones related to this there.
Then, introduce some shared experiences. Maybe they get trapped in a strange dimension together. In this new and dangerous place, they have to rely on each other's strengths. Goku's physical power and Frieza's cunning could be the keys to their survival. As they go through these experiences, they start to see each other in a new light and their relationship begins to change.
Yes, there are likely 'Bardock Kills Frieza' fanfics out there. The Dragon Ball universe has a huge fan base, and many fans like to create alternative storylines. You can try searching on fanfic websites like FanFiction.net or Archive of Our Own.
Sure. There are some sakura and frieza fanfictions. They often play with the contrast between Sakura's more earthly and human - like qualities and Frieza's otherworldly and often villainous nature. Some stories might have Sakura trying to reform Frieza, while others could be about them fighting against a common enemy.
Another concept could be a fusion of their powers. Imagine if Naruto was somehow able to absorb Frieza's power or vice versa. This could create a new and extremely powerful being. The story could explore how this new entity would interact with the two different universes. Would it be a force for good or would the power corrupt it? There could be a lot of internal conflict as the combined Naruto - Frieza entity struggles with its new identity and purpose.
Golden Frieza in crossover fanfiction often brings a new level of power and intrigue. His golden form is a significant power - up in the original series, and in fanfiction, it can be used to create interesting scenarios. For example, he could be paired with characters from other universes, leading to epic battles or unexpected alliances.