The setting of the fanfiction also plays a crucial role. If it's in a fantastical world, the 'forces of love' could have magical or otherworldly manifestations. For example, they could be represented by love - themed spells or entities that Marco has to interact with. This can add a layer of mystery and adventure to the story.
Marco could be developed by exploring his internal conflict. As a demon, he might have new instincts that go against his human values. For example, he may struggle with the urge to be more aggressive or use dark magic when he used to rely on his wits and martial arts skills.
Aokiji Robin fanfics often focus on their contrasting personalities. Aokiji is usually depicted as calm and detached, while Robin is more mysterious and knowledge - hungry. So, these fics play with how they interact given these differences.
One common theme is friendship. Since Marco has many friends in the show, fanfictions often explore the depths of his friendships, like how he supports his friends and how they support him in return.
There are many great fanfictions about Star and Marco. Some might focus on their adventures that could have happened off - screen in the show. For example, a fanfiction could explore a parallel universe where they have different powers but still their strong bond remains.
One common theme is identity. Since Marco is now a female, exploring how this new identity affects her relationships and her role in the story is often seen. For example, how does she interact with Star differently now? Another theme is power. Some fanfictions give Fem Marco new powers, and the exploration of how she uses and controls these powers is a big part of the story.
One popular 'Aokiji Robin' fanfic is 'Frozen Bonds and Ancient Secrets'. It delves into their complex relationship against the backdrop of the One Piece world. The story weaves together their individual pasts and how they might interact in various situations.
One great 'Star vs the Forces of Evil Marco fanfiction' is 'Marco's New Adventure'. It takes Marco on a journey through a parallel dimension where he has to use his wits and skills in a completely different way than in the original series.
Perhaps Marco is injured while trying to protect Star from an assassin sent by one of the villains in the series. This could lead to a story where Star blames herself for his injury and has to overcome her guilt while also taking care of Marco and finding a way to stop the assassin from coming back for another attempt.