His character could also develop in terms of his powers. Maybe the abandonment was related to his latent magical abilities. He could start exploring and mastering his powers more in the fanfic. Thor's presence could either be a hindrance or a help. If it's a help, Thor could encourage Loki to use his powers for good, which would be a big step in Loki's character development.
Well, there are 'child loki fanfic' that delve into his feelings of being an outcast even as a child. Since he's different from the typical Asgardian, these stories might show how he coped with loneliness and how he started to build the walls around himself that we see in the grown - up Loki. They can be quite interesting as they give a new perspective on his character development.
One possible plotline could be Loki's journey of self - discovery. After being abandoned as a child, he might struggle with feelings of unworthiness. Thor could then play a role in helping Loki realize his true potential. Maybe Loki initially resents Thor for having a more 'normal' upbringing, but as the story progresses, they come to understand each other better.
Thor is an obvious choice. As his brother, their relationship can be explored in new ways when Loki is a child. Thor can be protective and also try to guide Loki. Another great character to pair with child Loki is Captain America. Steve Rogers' sense of justice and leadership can have a positive impact on Loki. He can teach Loki about values and how to be a hero. And then there's Wanda. Her powers and her own complex past can make for an interesting connection with Loki. She can understand his struggle with his identity to some extent.
First, you need to research Loki's character. Know his traits, his backstory, especially his childhood in the original lore. Then, think of an interesting plot. It could be something like a day in the life of child Loki where he discovers a new part of Asgard or a secret about his powers.
I don't support or promote the concept of 'child bride' as it is unethical. However, if you are interested in regular Loki fanfics, you can check out Archive of Our Own (AO3). There are many well - written Loki - centered fanfictions that explore different aspects of his character, relationships in a proper and consensual way.
I'm not very familiar with this specific fanfic. However, generally, a fanfic about Loki and Thor might explore their complex relationship in the context of the Marvel universe. If Loki is intersex in this fanfic, it could add an interesting layer to the character's identity and how they interact with Thor.
Well, if we are to re - work this in an ethical way, perhaps a theme could be about Loki protecting a young girl from an arranged marriage (not as a child bride situation). He could use his powers and cunning to help her gain freedom and independence.
One alternative could be character - centric stories that focus on Loki's growth and development. For example, exploring his backstory, his relationships with other characters like Thor or Odin in a non - sexual way. Another option is to create stories where Loki is on a quest, facing challenges and using his intelligence and magic to overcome them.