Love and passion are very common themes. Since it's often about Damon, there's usually a strong sense of attraction and a complex relationship. For example, in many of these fanfictions, the OC might be initially hesitant about getting involved with Damon because of his reputation, but then they can't resist the pull towards each other.
Transformation is also a theme. The OC might change Damon in some way, or vice versa. Maybe the OC helps Damon become a better person, or Damon's presence in the OC's life makes her more confident and bold. This theme of growth within the relationship is something that makes these fanfictions really interesting.
One common theme is love triangles. Since it involves Damon, Stefan and an OC, often there's a complex love situation. For example, the OC might be attracted to both brothers in different ways.
A common theme is the forbidden love aspect. Since Damon has his own complex history and often behaves in a morally ambiguous way, a relationship with an OC is often portrayed as something that goes against the norm or is difficult to accept. Another theme is redemption. The OC might be the catalyst for Damon to seek some form of redemption in his life.
One common theme is the power struggle. Damon's possessiveness often leads to a tug - of - war between his desires and the OC's independence. Another theme is the idea of protection. His possessive nature can be seen as a form of protecting the OC from other threats in the supernatural world.
One common theme is the idea of a forbidden or unexpected love. Since Bella and Damon are from different fictional universes, their relationship is something that goes against the norm in their respective stories.
Love and passion are common themes. Since it's lemon fanfiction, there is often a strong focus on the physical aspect of their relationship as well as the emotional connection.
A frequent theme is the exploration of identity. The OC may have to re - evaluate who she is when she gets involved with Damon. For example, she might become part of the supernatural community, which changes her self - perception. Also, loyalty is a big theme. Damon and the OC have to show loyalty to each other, especially when facing external pressures. For instance, when other vampires or supernaturals might not approve of their relationship. And of course, there's the theme of family. They create a new family unit through their marriage, which includes not only themselves but also the friends and allies they gather along the way.
One common theme is redemption. Damon has a dark past, and in many OC fanfictions, his love for the OC character leads him to seek redemption. For example, he might try to make up for his past wrongdoings to be worthy of the OC's love. Another theme is the power of love to change. The OC's love can make Damon more empathetic and less ruthless. Also, the theme of forbidden love often comes up. Since Damon is a vampire and there are usually some rules or conflicts in the supernatural world, their love is often seen as forbidden, which adds to the allure and drama of the story.
One common theme could be adventure. Since 'the doctor' is often associated with traveling through time and space, the 'oc' can get involved in these exciting adventures. Another theme might be romance, as the relationship between the doctor and the oc is explored in different ways.
One common theme could be the power dynamic between the Joker and the OC. Since the Joker is such a complex and powerful character, exploring how an OC interacts with him in terms of power can be interesting.
Another theme could be self - discovery. The oc might be on a journey of self - discovery while being involved with Jasper. And the lemon elements can be seen as a part of that journey, a new experience that helps the oc understand themselves better in the context of the relationship. Also, power dynamics can be a theme, especially considering Jasper's character. The relationship might involve some give - and - take in terms of power, which is sometimes reflected in the lemon parts as well.