Frieza's victims in the manga included many powerful fighters. For instance, he eliminated Dende. His actions were driven by his cruel and power-hungry nature.
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.
In the manga, Goku managed to kill Zamasu by combining his strength with Vegeta and performing a joint attack. They also exploited Zamasu's weaknesses to gain the upper hand.
In some lemon fanfiction, their interaction can be filled with tension. Goku, being the good - natured Saiyan, may be initially wary of Frieza. But as the story progresses, they might find common ground. For example, they could start to respect each other's power.
It could develop through mutual admiration for each other's power. Goku is always looking for strong opponents to test himself against, and Female Frieza is no slouch in the power department. As they spar and train together, they might begin to respect each other more. This could lead to a friendship where they exchange fighting techniques and stories of their battles. Over time, this friendship could deepen into a more meaningful relationship where they trust each other completely.
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.