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 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 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.
One great Lex Luthor OC fanfiction is 'The Luthor's New Ally'. It offers a fresh take on Lex's character by introducing an original character who challenges his views in unexpected ways.
It can be disrespectful to the original source material and the intentions of the creators. The character of Lex Luthor has complex traits that should be explored in more meaningful ways.
You can start by looking on fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfics from various fandoms, including DC Comics where Harley Quinn and Lex Luthor are from. Just use the search function and type in 'Harley Quinn x Lex Luthor' to see the available stories.
There's also 'The Unlikely Alliance'. In this fanfic, Superman and Lex Luthor find themselves in a situation where they have to protect a common interest. It's interesting because it shows how their powers and intelligence can be used in tandem, despite their long - standing enmity. The author does a great job of building tension and then resolving it in unexpected ways.
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.