One common theme is the power struggle. Given the nature of the Continuum world, there are often power dynamics at play between different groups and Kiera and Alec are right in the middle of it in many fan fictions.
The relationship between Kiera and Alec is also a very common theme. It can range from a platonic partnership to a more romantic entanglement. Writers often explore how their different backgrounds and goals can either bring them closer or drive them apart in these fan fictions.
I also like 'Kiera and Alec: United Front'. This fan fiction focuses on how Kiera and Alec form a stronger alliance to face the various threats in the Continuum world. It has a lot of action scenes as well as some great dialogue that really captures the essence of their characters.
Another theme is friendship and loyalty. Since the story has a group of characters, their relationships are often explored. Fan fictions show how they support each other through tough times and how their loyalty is tested.
One common theme is loyalty. Their parabatai bond is a central part of their relationship in the original story, and fan fictions often explore the depth of that loyalty. They might face situations where their loyalty to each other is tested, like when dealing with different factions within the Shadowhunter community.
One common theme is friendship. Fan fictions often show the strong bond between the Blackpink members. They support each other through various challenges in the stories.
Love is a very common theme. Their relationship, which is between a Shadowhunter and a warlock, is full of challenges and the fanfics often explore how they overcome these through love. Another theme is acceptance. Alec has to accept Magnus's different lifestyle as a warlock, and Magnus has to accept Alec's duties as a Shadowhunter.
Overcoming obstacles is another theme. Fanfictions often show Maurice and Alec dealing with the social and family barriers that come their way. For example, in some stories, they have to face the disapproval of Maurice's family, but they still hold on to each other.
One common theme is friendship. Many fanfics explore the deepening of the friendship between Alec and other characters. For example, how Alec and Clary become closer friends over time and support each other through various difficulties.
One common theme could be the reactions of the people around Alec. His friends, family, or partners might have different responses to his pregnancy, ranging from shock to support.
One common theme is power. Alec has a lot of power in the Twilight universe, and fanfictions often explore how he uses or struggles with it. For example, some stories might show him trying to control his powers better.
Another theme is the struggle against prejudice. Since they are from different 'worlds' in the story, they face a lot of judgment from others, and fanfictions often deal with how they overcome this. Also, the theme of self - discovery is quite common. Both characters grow and learn more about themselves through their relationship with each other.