There could be a fanfic where Finn's death is a sacrifice to save Ooo from a great evil. In this story, his death might not be in vain as it inspires others to be braver. Maybe Marceline, who has seen a lot of loss in her long life, becomes a mentor to the younger characters as they cope with Finn's death, teaching them about the importance of memory and how to keep Finn's spirit alive.
One interesting fanfiction could be where Finn's death is a self - sacrifice to save Ooo. In this story, he might face an unbeatable enemy and choose to give his life to protect his friends and the land he loves. Another could be a more emotional take where Finn dies of an incurable disease, and his friends have to come to terms with his loss and remember all the good times they had with him.
Maybe in a fanfic, Finn's death could be part of a time - traveling accident. He could get caught in a time rift while trying to save someone or something important. His death would then cause a chain reaction in the timeline of Adventure Time. The fanfic could focus on how the other characters try to fix the timeline to bring Finn back or at least come to terms with his loss.
It can be quite divisive. Some fans who are very attached to Finn may be really sad or even angry about the idea of him dying in fanfics. They might see it as a negative take on the character they love. However, others may appreciate the exploration of deeper emotions and different storylines that such a concept brings. It allows for more complex character development for the remaining characters as they deal with grief.
Perhaps Finn's death is an accident. He could be exploring an uncharted area of Ooo and stumble upon a dangerous trap or ancient magic that he doesn't understand. His death shocks everyone in Ooo, and his friends start to question the safety of their continued adventures. This could lead to a whole new set of adventures for his friends as they try to come to terms with his death and make Ooo a safer place in his memory.
One common theme could be Finn's emotional struggles. For example, his insecurities about his role as a hero or his relationships with other characters. Another theme might be physical harm he endures during his adventures, like battles with monsters. And sometimes, the theme could be about how he copes with loss, which causes him a great deal of hurt.
Often, the theme of adaptation comes up. A female Finn has to adapt to the same world that the male Finn knew, but with the added factor of being a different gender. This can lead to her having to prove herself more in some cases. Also, the theme of sisterhood or female friendships might be explored more in these fanfics. She could form new bonds with female characters in the Adventure Time universe that weren't as prominent in the original with male Finn.
One interesting fanfiction could be where Older Finn goes on a quest to find a long - lost relic from his past adventures. It might involve him using his years of experience and wisdom to overcome various challenges.
One interesting theme is Finn's search for identity. Since he's a human in a strange land full of magical beings, he often questions who he is and where he belongs. Another theme could be his relationships, like his brotherly bond with Jake or his complex feelings towards Princess Bubblegum.
One common theme could be Finn getting embarrassed in front of his friends. For example, he might trip and fall while trying to show off a new skill. Another theme could be his romantic embarrassments, like when he tries to ask a girl out and stumbles over his words.
Well, I'm not sure of the exact title, but you can try looking on fanfic platforms like Archive of Our Own. There are likely to be several 'Adventure Time' female Finn fanfics there. You can search using keywords like 'Adventure Time', 'female Finn' and sort through the results. Some fanfics might be part of a series, so keep an eye out for those as well. They can offer a more in - depth look at the concept of a female Finn in the Adventure Time universe.