Maybe the mermaid is cursed and the only way to break the curse is to be part of a successful Glee club. So she has to learn all about human music and performance. Her mermaid - like charm and beauty could attract new members to the club, but she also has to deal with the jealousy and insecurities of some of the existing members. This would add a lot of drama to the fanfiction.
The Little Mermaid's belly could be the key to a mystery. For example, there could be an ancient riddle in the ocean that says only a mermaid with a special mark on her belly can unlock a certain power. The Little Mermaid discovers she has this mark. So she embarks on a journey to figure out what this power is and how to use it to benefit the ocean and her fellow sea creatures. It could involve her meeting other mermaids or sea wizards who can help her understand the mystery.
Imagine a region in the Pokemon world where there is a festival related to diapering Pokemon. Trainers from all over come to show off their best - decorated Pokemon diapers or compete in diaper - changing races. This would be a really creative and fun way to incorporate the concept. It could also be a way for different trainers to bond and share their experiences with taking care of their Pokemon in this aspect. Also, there could be special rewards for the winners, like rare Pokemon items or new types of Pokemon diapers that have unique abilities.
Perhaps the lemons are a form of currency in the demon realm. Naruto, in his interactions with the demon king, has to trade lemons for information or help. This could lead to comical situations as Naruto tries to gather enough lemons, and also serious moments when the demon king demands more lemons than Naruto can easily obtain.
Well, in a Young Justice fanfiction, the concept of Naruto being immortal could be integrated in various ways. One way could be through some sort of magical or scientific experiment gone wrong that gives him immortality. Maybe it's a meta - human experiment in the Young Justice universe that accidentally gives Naruto the same powers as Vandal Savage, including immortality. Another possibility is that it could be a result of a powerful jutsu he uses that has unforeseen consequences and makes him immortal.
It could also be a character - based integration. A new character inspired by Dark Naruto could be introduced into the RWBY fanfiction. This character might have similar traits such as a thirst for power and a bit of an anti - hero complex. They could interact with the existing RWBY characters, causing conflict and also growth among them.
One way is to give the Xenomorph - like Pokemon a unique typing. For example, it could be part Dark and part Poison type. This would make its attacks and weaknesses different from regular Pokemon. Another way is to have it with an ability that is related to its Xenomorph nature, like being able to move quickly through vents or small spaces, similar to how Xenomorphs do in their original lore. You could also make its evolution method really strange, like it evolves when it 'infects' a certain number of other Pokemon.
One way to integrate it is to have a mad scientist - type character introduce the nanites into Naruto's body. Maybe this character is an outcast from a hidden village who has been secretly researching nanotechnology. He sees Naruto as a perfect test subject and implants the nanites without Naruto's full knowledge at first.
Well, one way is through a training arc. Imagine Naruto's training takes him to a secluded place where an old master lives. The master has a unique training method that involves wearing a Yukata while performing certain ninja techniques. Naruto would have to adapt to the new clothing style while still maintaining his ninja abilities. Also, Naruto could be involved in a rescue mission where the kidnapped person is held in a place where Yukata are an important part of the environment. He might have to disguise himself in a Yukata to blend in and save the day.
Their relationship could develop uniquely if Rachel takes on a teaching role for the younger glee club members under Will's guidance. This role reversal would force them to see each other in new lights and create a deeper bond.
In 'glee born this way fanfiction', the plot could revolve around the creation of a performance in the Glee club that is centered around the 'born this way' song. This could lead to different character arcs, like some characters having conflicts about how to best represent the message, while others are fully on board from the start.