Another theme could be character development. Writers might use the conflict between the two characters as a way to show how they grow and change over time. For example, they could start as bitter enemies and gradually come to understand and respect each other. This can add depth to both characters.
One common theme could be rivalry. Since it's 'vs' in the title, many fanfics might explore the competitive nature between Beckett and Meredith, whether it's in a professional setting or some other context.
One common theme is friendship. Many fanfics start with them as friends and then explore how that relationship can evolve. Another theme is mutual understanding. Since they have different personalities, showing how they come to understand each other is popular.
You can try searching on popular fanfic websites like Archive of Our Own (AO3). They have a large collection of fanfictions, and there's a good chance you'll find Beckett vs Meredith fanfic there.
A common theme is friendship. Many fanfics explore how Beckett and Alexis become friends and the bond they share. Another theme is growth, as they both develop as characters within the fan - created stories.
One common theme is loyalty. Their loyalty to each other, whether it's in the face of danger or personal challenges, is often explored. For example, in many fanfics, they stand by each other no matter what.
One common theme is family bonds. Since it's about a father - son relationship, many stories explore how they communicate, misunderstand, and then reconcile. For example, a story might show the son struggling to live up to the father's expectations at first, but then they grow closer as they understand each other better.
One common theme is the struggle between the vampire nature and human morality. Beckett, as a vampire, often has to grapple with his blood - thirsty instincts while still holding on to some human values.
Friendship is also often explored. Maybe they start as acquaintances and gradually become really good friends. And there could be themes related to self - discovery. As they interact, they learn more about themselves. For example, Lily might discover a new side of herself because of Beckett's influence. There can also be some mystery - themed fanfics where they solve some kind of mystery together.
One common theme is the anticipation and excitement of new life. Meredith's character is often shown looking forward to motherhood, despite the challenges that come with it.
In many 'Alex and Meredith kiss fanfic', the theme of forbidden love is explored. Maybe they are in different relationships or there are external factors preventing them from being together. The kiss then becomes a moment of defiance against those odds. It adds a sense of drama and tension to the story, making it more exciting to read.
A common theme is redemption. Many fanfics explore whether Meredith could be redeemed or if there were parts of her that were redeemable despite her actions in the game. Another theme is power. Meredith had a lot of power and fanfics often look at how she used or misused it.