The theme of self - discovery is also quite prevalent. Through the relationship with Sans, the OC often discovers new things about themselves. They might become more confident or learn to face their fears, as the relationship with Sans acts as a catalyst for their personal growth.
One common theme is the discovery of the soulmate bond. Usually, the OC and Legolas start off not knowing they are soulmates and then gradually realize it through various events.
One common theme is the discovery of the soulmate bond. The OC usually has to figure out their connection to the Avengers. Another theme is acceptance. The Avengers have to accept this new person in their midst who is their soulmate. And of course, there's often the theme of love and loyalty as the relationships develop.
One common theme is the clash of cultures. Since T'Challa is from Wakanda, an advanced and unique African nation, and the oc often comes from a different background, there's a lot of exploration of how their different cultures interact. Another theme is the power of destiny. In these stories, it's often fated that they are soulmates and they have to overcome various obstacles to be together.
One popular sans oc soulmate fanfiction is 'Soulbound to Sans'. It has an interesting plot where the OC has a unique connection with Sans. The story is full of emotional moments and great character development.
Common themes often include emotional turmoil. The oc is suicidal, so there's a lot of internal chaos that Sans might either calm or exacerbate. There's also the theme of isolation. The oc may be feeling alone, and Sans can either break that isolation or be unable to reach the oc. Additionally, transformation is a theme. The oc may transform from a suicidal state to a more positive one because of Sans.
One common theme is anticipation. The characters are always waiting for the timer to reach zero, and this builds a lot of suspense. Another is destiny. Since it's about soulmates, the idea that they are fated to be together is often explored.
Fate is also a big theme. Fanfictions often play with the idea that the characters were always meant to be together as soulmates, no matter what they've been through. It gives a sense of destiny to their relationships, which adds a whole new layer of depth to the characters' stories in the Supernatural context.
Often, themes of friendship or rivalry might be present. They might start off as rivals but then develop an understanding or even a friendship. Another theme could be the contrast between their personalities. Lust Sans is known for his more flirty nature while Fell Sans has a more aggressive side, and how these play out in their relationship is a popular theme. Also, in some fanfictions, they might team up to face a common enemy or situation, which is also a recurring idea.
Another theme is friendship or partnership. They often come together to face challenges in the Underground. For example, in many fanfictions, they join forces to defeat a powerful monster or solve a mystery that threatens their world. This theme of unity despite their differences is really appealing.
One common theme is friendship. Since they are from different 'worlds' in the Undertale AU, their journey to become friends is often explored. Another theme is redemption. Sometimes Cross Sans might have a troubled past and Dream Sans helps him find a new path.