https://nightmareknights.com/
Here just ctrl+F "stories" and you'll find many old tibian stories written by players.
https://tibia.fandom.com/wiki/Library
Here you can find all tibian books.
https://www.reddit.com/r/Rookgaard/wiki/index/
Here just ctrl+F "knightmare" and you'll find stories written by the main lore creator in Cipsoft, also in other links you can find lore of Rookgaard, and history of NPCs, quests, items etc.
There's currently an active fansite called Tibia Tales that focuses on Fanfics (fan fiction stories) from players and admins from the website.
This might be a good option of what you're looking for.
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