Another interesting aspect could be creating new elven sub - races within the 'Throne of Elves' universe. You could describe their unique cultures, abilities, and how they interact with the main elven society.
One idea could be a fanfiction that focuses on an alternate ending where the main character makes a different choice at a crucial moment. Maybe she decides not to trust a certain ally and it completely changes the course of the story.
One idea could be exploring the backstories of minor characters in more detail. For example, delving into the past of a random cultist and how they came to be involved with the strange happenings in the world of 'the throne of worm'.
A plot could revolve around a Dark Elf sorceress who discovers a powerful and ancient magic that was lost. But this discovery attracts the envy and wrath of other powerful Dark Elves. She has to fight for her life and the right to keep this magic while also using it to her advantage in the cut - throat Dark Elf hierarchy.
A fanfiction could focus on an elf who is reincarnated into a human body in the Black Clover world. They struggle to adapt to the human way of life while still having their elf memories and powers. As they try to keep their identity a secret, they get involved in various adventures and form unexpected relationships with the characters from the original series.
A great plot might involve the traitor's family. How do they react to the accusations? Do they believe in the traitor's innocence? For example, a sister could embark on a journey to find evidence to prove her sibling's loyalty. This would add a lot of emotional depth to the fanfiction.
One idea could be exploring a side character's backstory. For example, a minor character in 'a throne of stars' might have a really interesting past that wasn't fully explored in the original. Maybe they were part of a secret organization before and their actions now are influenced by that past. Another plot idea could be a 'what if' scenario. What if the main character made a different choice at a crucial moment? It could lead to a completely different story arc and interactions with other characters.
One idea could be exploring the backstories of the minor characters in 'throne of babylon'. Maybe a character who was a servant in the palace has a secret past as a spy from another kingdom. Another could be a love story between a noble and a commoner set against the backdrop of the political intrigue in Babylon.
Well, you could write a fanfiction about the chicken's training journey. Show how it starts off as a weakling in the Nuclear Throne universe and through various challenges and battles, it gradually becomes stronger. Maybe it meets a wise old character who teaches it some unique skills. You can also add some comical elements, like the chicken constantly getting into silly situations while trying to master its powers, but in the end, it emerges as a formidable force.
One idea could be exploring Fenrys' backstory more deeply. Maybe show his life before he became part of the cadre. Another could be a love story involving Fenrys and a new character, perhaps a healer who tends to his wounds during a battle and they gradually fall in love. A third idea is to put Fenrys in an alternate universe where the events of Throne of Glass unfold differently, like if he was the one to find Celaena first.
One idea could be exploring Celaena's life before the events of the main series. Maybe her training with a different, more secretive mentor. Another could be a story where she has to team up with her enemies from the series for a common greater threat. For example, the king's men and Celaena having to work together to stop a dark magic invasion.