Well, there could be a plot where Lex Luthor's daughter has some latent powers that are awakened by Supergirl in a moment of crisis. This newfound power makes her a target for other villains, and Supergirl feels responsible for protecting her. As they spend more time together, they start to understand each other's perspectives. Maybe the daughter has a different view of the world than her father, and Supergirl helps her explore and embrace that, leading to a story of self - discovery and an unexpected bond between them.
The relationship might develop in a very complex way. Given Lex Luthor's daughter's background, she could be both intrigued and afraid of Supergirl. They could be forced into situations where they have to communicate, like when they are both captured by a new villain. During their captivity, they learn about each other's hopes and fears. Supergirl might talk about her desire to protect the city and its people, while the daughter might open up about her struggle to break free from her father's shadow. This mutual understanding could gradually transform their relationship from one of enmity or suspicion to one of trust and even friendship.
One plot idea could be that Supergirl and Batgirl team up to take on a new super - villain in Gotham. This villain has the ability to manipulate technology and is causing chaos. They combine Supergirl's super strength and flight with Batgirl's detective skills and martial arts expertise. Another idea is that they are transported to an alternate dimension where they have to find a way back home while facing different versions of their friends and foes. And a third idea could be that a powerful alien artifact is found in Metropolis and both girls must protect it from various forces that want to use it for evil, all while learning more about each other's worlds and abilities.
One idea could be a story where Lena Luthor discovers a new technology that could help Supergirl better protect the city, and they work together to develop it. It would be about their cooperation and how they use their respective skills to achieve a common good.
One interesting plot twist could be that Lex Luthor is actually related to one of the pure - blood wizarding families in the Harry Potter world. This completely changes the power dynamics and how he is perceived in the wizarding society. Another could be that Lex Luthor discovers a way to combine magic and technology in a way that no one in the wizarding world has ever thought of before, which gives him an edge over both wizards and Muggles.
One idea could be that the male self - insert (SI) has a unique power that complements Supergirl's. For example, he might have the ability to control technology, and together they fight against a cyber - villain who is trying to take over the city's power grid. Another plot could involve the male SI coming from a different dimension and having to adjust to the world of Supergirl while also helping her deal with an otherworldly threat that she's not familiar with. A third plot could be that the male SI is an ordinary human at first but gains powers through an accident and then he and Supergirl have to learn to work together as he masters his new abilities.
One common theme is the struggle between good and evil. Superman represents pure good, while Lex Luthor is often seen as the epitome of evil. Their interactions in fanfiction often revolve around this fundamental conflict, whether it's about Luthor trying to corrupt Superman or Superman trying to redeem Luthor.
One great storyline could be where Supergirl and Lena Luthor have to team up against a common enemy that is threatening both National City and L - Corp. This forces them to put aside their differences and really understand each other on a deeper level. Another could be a time - travel story where they go back in time and see how their relationship could have developed differently. There are also stories where Lena discovers Supergirl's true identity in a very unexpected way and they have to deal with the fallout.
Well, one possibility could be that Naruto, as Lex Luthor's son, might struggle with his dual identity. He has the ninja skills from his Naruto side and the scientific and strategic mind from Lex Luthor. Maybe he uses his unique combination of abilities to fight against new villains in the Naruto world who are also after Lex Luthor's technology or knowledge.
One interesting storyline could be Lex Luthor secretly funding a group of meta - humans to create chaos and then swoop in as a'savior' to gain public favor. This would play into his manipulative nature.
One common theme is power dynamics. Lex Luthor is a powerful and intelligent villain, and Harley Quinn has her own brand of chaos. Their interactions often explore who has the upper hand in different situations.