One possible reason in fanfiction is that Thor is influenced by the Asgardian society's view of Loki. Asgardians may generally distrust Loki because of his Jotun heritage. Thor, being part of that society, could be mean to Loki as a result. Also, if Loki has tried to steal Thor's thunder, literally or figuratively, like trying to take over his role as the protector of Asgard or getting credit for Thor's achievements in a fanfic, Thor would be likely to be mean to him.
When Thor is mean to Loki in fanfiction, it can lead to a downward spiral in their relationship. Loki, feeling constantly attacked, may lash out in more extreme ways. Thor, on the other hand, may double down on his meanness, believing it's the only way to deal with Loki. This can create a cycle of animosity where any love or brotherly bond they had is overshadowed by anger and distrust. For example, Loki could start to form alliances with Thor's enemies out of spite, and Thor would see this as confirmation of Loki's untrustworthiness, making the relationship even worse.
Well, Loki is often seen as more complex. He has a more ambiguous moral compass which makes his character more interesting in fanfiction. He can be a trickster, a misunderstood anti - hero, while Thor is more of a straightforward hero type.
There's 'Thor's Redemption in Loki's Arms'. In this story, Thor realizes his true feelings for Loki after a series of events that nearly tear Asgard apart. It's a tale full of emotion and character development.
One example could be a story where Loki's intersex nature adds a unique layer to his relationship with Thor. Maybe in the fanfic, Thor is initially confused but then becomes very accepting and protective of Loki. It could explore how Loki deals with his own identity in the context of Asgardian society, which might be less understanding compared to modern Earth concepts.
If Loki survived in Infinity War fanfiction, it could have led to a very different outcome. He might have used his trickery to deceive Thanos in some way. Maybe he could have pretended to be on Thanos' side while actually working against him. This would have added an extra layer of intrigue to the story as the other characters would have been unsure of his true motives.
Loki in lemon fanfiction can be very seductive and mysterious. His character is full of layers, and he often uses his charm to get what he wants, whether it's power or a closer relationship with Thor. Thor is usually shown as a protector. He has a big heart and his love for Loki, be it brotherly or something more in these fictions, makes him vulnerable. For example, in some stories, Thor's loyalty to Loki is tested when Loki gets into trouble due to his schemes. And Loki's actions are sometimes driven by his need for Thor's attention or acceptance.
One common theme is family. Their brotherly bond, whether it's strained or strong, is often explored. Another theme is redemption, especially for Loki as he has made many mistakes. Also, power and how they both deal with it, Thor with his more straightforward use and Loki with his more cunning approach, is a frequent theme.
One interesting Young Loki and Thor fanfiction could be about their adventures in Asgard as kids. Maybe they get into trouble while exploring a forbidden part of the realm.
Maybe Loki returns after being presumed dead. Thor is overjoyed at first, but then realizes Loki has some secrets he's been keeping. They have a tense but ultimately heartwarming conversation as they catch up on all that has happened.
One common theme is redemption. Female Loki might be trying to redeem herself in Thor's eyes or in the eyes of Asgard. For example, she could have made some mistakes in the past and is now on a path to make amends.