Love and acceptance is also a big theme. Fanfics often show how they come to accept each other's quirks and flaws as they fall in love. It's about two people from very different worlds finding a connection that is both unexpected and beautiful.
One way to develop their relationship is through acts of kindness. Maybe Xavier gives Wednesday a piece of his art that he made especially for her, which shows that he sees her in a special way. Wednesday, in turn, could protect Xavier from a bully at school. Another aspect could be through humor. They could start making inside jokes based on their strange experiences at school. As they get more comfortable with each other, they might even start to develop feelings that are more than just friendship. For instance, Xavier could find himself getting jealous when another student shows interest in Wednesday, which would be a sign of his deeper feelings for her.
Sure. It's an unlikely love story. Wednesday's gothic nature and Xavier's more mainstream-ish charm create a contrast. But that's what makes it interesting in fanfictions. They might start off as not liking each other much, but then gradually discover things about each other that draw them together.
I really liked 'Shadows and Paintbrushes'. In this fanfic, Xavier uses his art to understand Wednesday better. It has some really interesting scenes where he tries to capture her essence in his paintings, and their interactions are filled with a lot of unspoken emotions. It's a great read for fans of the pairing.
One great Wednesday and Xavier fanfiction is 'The Dark Bond'. It delves deep into their complex relationship within the spooky setting. It shows how their personalities, Wednesday's dark and brooding nature and Xavier's more tortured artistic side, interact and create a unique bond.
Fanfiction could also explore how Wednesday's family views Xavier. Her family is quite unique and has their own set of values. If Xavier starts getting closer to Wednesday, her family might be initially suspicious of him. But as they see how he treats Wednesday and how he respects her dark side, they could come to accept him. This would add an interesting dynamic to the Xavier - Wednesday relationship.
One popular type of Xavier and Wednesday fanfiction could be a story where Xavier uses his artistic abilities to try and understand Wednesday better. He might paint her in different settings, each representing a different aspect of her complex personality. This could lead to some really interesting interactions between them as Wednesday tries to figure out why he's so intrigued by her.
Romance is a big theme. Since they are two very different yet interesting characters, many fanfictions explore how a romantic relationship could develop between them. It might start from a simple friendship or rivalry and gradually turn into love. Another theme is mystery. Given the spooky and mysterious setting of Nevermore, they often get involved in solving mysteries together in fanfictions, which also helps in deepening their bond.
You can start by looking on Archive of Our Own (AO3). It has a large collection of fanfiction for various shows, including Wednesday. Just search for 'Wednesday and Xavier' and you'll get a bunch of results.
A less common but still interesting trope is the 'swap of powers' or 'shared understanding' trope. Some fanfictions explore what would happen if Wednesday somehow gained a bit of Xavier's psychic powers or vice versa. This leads to a deeper understanding between them and often drives the plot in unique ways as they navigate this new connection.