A possible fanfiction could focus on a group of Saiyans who are trapped in a dimension where they can only watch the Goku vs Frieza fight on repeat. They start to notice small details in the fight that they hadn't before, like the exact moment Goku's power level spikes or how Frieza is trying to adapt his strategy. This newfound knowledge could then be used by them in some way when they eventually break free from that dimension.
Trunks would also be interested. He has his own experiences with fighting powerful foes and would be eager to see how Goku, a great Saiyan warrior, fares against Frieza. Also, the younger Saiyans like Goten might be interested. They've heard stories about Frieza and would be excited to see their father or other Saiyan heroes in action against such a notorious villain.
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.
One idea could be to cross UI Goku with a character from another popular anime, like Naruto. UI Goku could end up in the Hidden Leaf Village and have to deal with the different ninja powers and politics there. Maybe he'd have to train some of the young ninjas, which would be really cool as his fighting style is so unique.
It's hard to say for sure. Both Goku UI and Jiren are incredibly powerful in the manga. Their strength and skills are on par, so it could go either way depending on various factors.
First, decide which character or universe you want to cross UI Goku with. This is crucial as it will set the tone for your whole story. Then, think about how Goku gets to this new world or meets the new character. It could be through some kind of interdimensional portal or a magical spell gone wrong.
Honestly, the best writers are the ones who can take the basic concepts of Goku and Fem Frieza and turn them into something completely different yet still in - character. Some writers do this by exploring different genres within the fanfiction. So instead of just an action - packed story, they might write a romantic comedy or a mystery involving Goku and Fem Frieza. These writers are often the ones who can surprise readers with their creativity and fresh perspectives.
Well, friendship is also a theme. Despite their differences, they might form an unlikely friendship. In some fanfictions, they learn from each other. Goku might learn about strategy from Fem Frieza, while Fem Frieza could learn about determination and the will to protect from Goku. And of course, adventure is a big theme. They could go on quests together, exploring new planets and facing new challenges.
One common theme is redemption. Frieza is often portrayed as having a chance at redemption through his interactions with Goku. For example, in some fanfics, Goku's unwavering belief in the good in people (or in Frieza's case, beings) starts to make Frieza question his own evil ways.