There's also the theme of self - discovery. Both characters may go through a journey of understanding themselves better because of their relationship. For example, Alec might discover a more intellectual side of himself through Magnus, while Magnus could find a more carefree and passionate side of himself through Alec. This exploration of self within the context of a relationship is often explored in these fanfictions.
Another theme could be the power of music in bringing people together. Alec's music might be the initial connection between him and Magnus. Maybe Magnus is initially uninterested in the rock star lifestyle but gets drawn in by Alec's music and the passion behind it, which is a popular trope in such fanfictions.
Another option is Tumblr. There are a lot of fanfiction writers and fans who share their works or reblog interesting fanfictions. You can search for relevant tags like #RockStarAlec #ProfessorMagnusFanfiction. Sometimes, you can also find fanfic writers who are active on Tumblr and might have more stories on their personal blogs.
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.
Love is a very common theme. Their love story, how they overcame differences to be together. Another is the theme of acceptance, like Alec accepting Magnus' warlock nature and Magnus accepting Alec's Shadowhunter duties. And also the theme of family, as they both have different family backgrounds and how they merge their families in a way.
A frequent theme is also the power dynamics. Magnus has his powerful magic, and Alec has his position in the shadowhunter world. How they balance this in their relationship is often explored. Also, the theme of family acceptance is common. Alec's family and their reactions to his relationship with Magnus are often part of the stories.
One common theme is the exploration of new relationships. The addition of an OC often creates a new dynamic between Alec and Magnus. For example, the OC could be a mediator in their relationship, helping them understand each other better.
Another theme is self - discovery. In human fanfictions, they might be on a path to find out who they are without the trappings of their original magical or shadowhunter identities. They learn about their strengths and weaknesses as normal humans.
A major theme in magnus x alec fanfiction is the exploration of power dynamics. Magnus is a powerful warlock and Alec is a shadowhunter. How they balance their different levels of power and influence in their relationship is often explored. Also, the theme of acceptance is quite prevalent. They come from different worlds, and their journey towards accepting each other's differences is a key part of many stories. For example, in some fanfictions, Alec has to come to terms with Magnus's long life and his different magical practices.
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.
One common theme is acceptance. Alec has to come to terms with his feelings for Magnus in a world that may not always be accepting, and Magnus has to accept Alec's insecurities and growth. Another theme is sacrifice. They often have to sacrifice personal desires for the greater good of their relationship and the Shadowhunters world.
Well, in Magnus x Alec lemon fanfiction, a frequent theme is the discovery of each other's desires. Since they come from different backgrounds, Magnus being a warlock and Alec a Shadowhunter, there's a lot of room for exploring how they understand and fulfill each other's needs. Additionally, themes of acceptance, both within themselves and from their respective communities, are quite common. The 'lemon' aspect can sometimes be used to show the deepening of their bond and the breaking of barriers between them.