Another possibility is a crossover with Re:Zero. The time - looping concept of Re:Zero could be introduced into Log Horizon. Characters from Log Horizon might have to deal with constantly resetting situations and use their wits to break out of the loops and continue their journey in their own world.
One idea could be that the characters from Sword Art Online find themselves in the world of Log Horizon. They could be confused by the different rules of the game world in Log Horizon, especially the unique economic and social systems. For example, Shiroe's knowledge of the game mechanics could either be a great help or a source of conflict when dealing with the SAO characters who are used to a more combat - centered gameplay.
One idea could be exploring the backstories of minor characters in Log Horizon. For example, the daily life of an NPC who has started to gain self - awareness. Another could be a time - travel plot where a character goes back to a crucial moment in the game's history and tries to change things. Or perhaps a story about a new guild forming in the world of Log Horizon, facing unique challenges different from the main guilds in the original story.
There are fanfictions that center around the relationships between the characters. For example, a story about how two characters who were initially at odds gradually come to understand and respect each other, and perhaps even form a friendship or something more. This can add a new dimension to the existing character dynamics in Log Horizon.
A cool Horizon Zero Dawn crossover fanfiction idea is a crossover with the Legend of Zelda. Picture Aloy in the world of Hyrule. She could use her skills to solve some of the puzzles there and maybe help Link in his battles against Ganon. She might be intrigued by the different types of magic and technology in Hyrule compared to her own world. Also, her spear - fighting skills could be a great addition to Link's combat techniques.
Another storyline might focus on a different take of an existing event in Log Horizon within the fanfiction. Maybe the Catastrophe that sent everyone into the game world happened in a slightly different way, and this alteration leads to a whole new set of challenges and solutions for the characters. It could explore how the players adapt to this different version of the Catastrophe.
One interesting Log Horizon OC fanfiction could be one where the original character is a powerful mage from a far - off land who comes to the world of Log Horizon with unique spells. This can add new elements to the existing magic system in the game world.
One interesting concept could be the use of magic in the world of Log Horizon. In Harry Potter, magic is a natural part of the world, but in Log Horizon, it's more of a game - like system. So, a fanfiction could explore how wizards from Harry Potter would adapt to the rules of Log Horizon's magic system. Another concept could be the mixing of races. Log Horizon has a variety of races like the Cat People and the Dwarves. Imagine a scenario where a Hogwarts student meets these races. It could lead to some really fun and unique interactions.
First, you need to be familiar with both the Log Horizon universe and the other universe you want to cross it with. Read up on their characters, settings, and rules. For example, if it's a crossover with Naruto, understand how chakra works in Naruto and how the game mechanics work in Log Horizon.
The world - building in Log Horizon light novels is quite fascinating. It creates a detailed virtual world where the characters are trapped. The complex relationships between the characters, both in terms of cooperation and conflict, add depth to the story. For example, the different guilds have their own agendas and ways of operating, which often lead to various plot developments.
The most interesting aspect could be the adaptation of the characters. For example, Harry Potter is a hero in his own world, but in Log Horizon, he might have to learn new skills and adapt to a different kind of adventure. His leadership skills could be put to a different test. Hermione might use her intelligence to analyze the Log Horizon system and find new ways to use magic within it. And Ron's loyalty and humor could bring a new dynamic to the relationships in Log Horizon. All these character developments in a new and different world make for a very engaging fanfiction.