One common theme is probably the journey of their relationship, like how they first met and overcame initial misunderstandings. It often shows their growing affection for each other.
Well, one place to look for such fan fiction could be Archive of Our Own (AO3). There are often many talented writers who create S0encer and Derke - related romance stories there. Just search for the relevant tags on the site.
One common theme is the simplicity and innocence of love. Hobbits are known for their simple lives, and this is often reflected in their romances. Love often blossoms in the midst of daily activities like gardening or baking.
One common theme is the idea of overcoming differences. Since they may be from different backgrounds or houses in the wizarding world, the fan fictions often focus on how they bridge those gaps. For example, in many stories, Harry's Gryffindor bravery and Theodore's more reserved nature from his own house are things they have to work through.
A common theme is the forbidden love aspect, considering Samara's Justicar code. It adds an element of tension.
One common theme is the exploration of the band members' personalities. Fan fictions often dig deeper into what the members might be like off - stage.
Love against all odds is also a frequent theme. There are often external forces like dark magic, or the disapproval of the wizarding community that try to keep Harry and the creature apart. But their love prevails, showing the power of love in a rather fantastical setting. This makes the stories very engaging and full of emotional highs and lows.
One common theme is sacrifice. Often, either Shepard or Ashley has to make sacrifices for the sake of their relationship or the greater good. For example, they might give up a personal mission to be with the other.
A common theme is the struggle between their different responsibilities. Mera has her duties in Xebel and Aquaman has to rule Atlantis. Their love often has to navigate these political and leadership obligations.
A common theme is self - discovery. Wendy often goes on a journey, either physical or emotional, and learns more about herself. For example, in many fan fictions she might face a difficult situation that forces her to look inward.
One of the common themes is redemption. Characters may try to make up for their past mistakes. For example, a character who has done something bad in the original show might seek redemption in the fan fiction. Also, exploration is a theme. They might explore new parts of the world they are in. And power struggles are also common, as different characters or groups vie for control.