A prevalent theme is acceptance. Marco has to accept Tom's devilish nature, and Tom has to accept Marco's human quirks. Also, the theme of adventure often comes up. They go on all sorts of adventures together, which helps strengthen their relationship. In some fanfictions, there's also a theme of self - discovery, as they learn more about themselves through their relationship with each other.
One common theme is possessiveness. Tom, in his yandere state, is often extremely possessive of Marco. He doesn't want anyone else to be close to Marco and will go to great lengths to keep others away.
The interesting part could be the exploration of their relationship in a different light. Since lemon usually implies a more mature or romantic aspect, it can show a deeper emotional and physical connection between Tom and Marco that might not be as fully explored in the original source material.
Well, the theme of acceptance is quite common. Tom, with his demon nature, and Marco, with his own quirks, learn to accept each other fully. Also, adventure is a popular theme. They might go on quests together, facing challenges that strengthen their bond. For example, in many fanfictions, they have to battle supernatural forces and in the process, their relationship deepens.
A common theme is friendship turned into something more. Their initial relationship as friends or rivals often evolves romantically. Another theme is self - discovery. As they interact more, both Tom and Marco learn more about themselves. Also, acceptance is a theme, especially in terms of accepting each other's flaws.
One popular tom x marco fanfiction could be 'The Unlikely Bond'. It explores how their relationship develops in a unique and interesting way, with them going on adventures together and gradually realizing their deep connection.
Star would be a likely candidate to rescue Marco. She has strong magical abilities and a deep friendship with Marco. She would stop at nothing to find him and bring him back safely.
One popular 'yandere Tom x Marco fanfiction' is 'Tom's Obsession'. It delves deep into Tom's yandere tendencies towards Marco. In this fic, Tom's possessiveness over Marco is explored in a really interesting way, showing how his character can take a darker turn when it comes to his feelings for Marco.
Well, there are quite a few. 'Marco's Encounter with Tom' is a great one. It delves deep into their personalities and how they interact. In this fanfiction, their friendship (or something more) is developed through various events like facing a common enemy. Also, 'The Red and the Blue' is interesting as it focuses on their contrasting natures and how that can either pull them apart or bring them closer.
Well, another place could be Tumblr. There are many fan communities on Tumblr that share and discuss fanfiction. You might find some Tom x Marco lemon fanfiction by searching relevant hashtags or by following the right blogs. However, Tumblr's search can be a bit tricky sometimes, so you may need to dig a bit deeper.