Yes, there are quite a few. You can start by looking on fanfiction websites like Archive of Our Own. Some fanfictions might explore Bell's fear in relation to his complex relationship with Hestia, perhaps due to her over - protectiveness or his own insecurities in the face of her expectations.
One great 'Danmachi Aiz x Bell Fanfic' is 'The Encounter'. It beautifully portrays the relationship between Aiz and Bell. The story focuses on how they train together and gradually develop deeper feelings for each other. The author does a wonderful job of capturing the essence of their characters from the original series.
He might become very withdrawn. Bell could start to isolate himself from others, especially those associated with Hestia. He may no longer trust as easily as he did before.
A common theme is the growth of their relationship. It could be a slow - burn type of relationship where they gradually become closer. Another theme is adventure, as they often go on dungeon crawls together in the fanfictions.
One common theme could be the exploration of Bell's emotional turmoil after the betrayal. It might show his struggle to trust again. Another theme could be the consequences for the one who betrays Bell, perhaps facing the wrath of his friends or the Gods. Also, the rebuilding of Bell's relationships in the face of such a betrayal can be a theme. Fanfic writers might use this as an opportunity to show Bell's growth and resilience as he overcomes the pain of being betrayed.
A jealous rival could be a likely betrayer. Maybe someone who is envious of Bell's popularity or his relationship with certain characters. For example, another adventurer who feels overshadowed by Bell might betray him to gain an advantage. Another possibility is a character who is being manipulated by a darker force. They might not have wanted to betray Bell originally but are forced to under the influence of some evil power.
Bell and Riveria are the main characters in this light novel. Bell, as a young and aspiring adventurer, drives the story forward with his dreams and efforts. He faces numerous difficulties and overcomes them in his growth process. Riveria, with her own set of abilities and personality, is closely related to Bell's story. She might offer him advice, help him in battles, or be involved in some sort of emotional connection with him. These two characters form the core of the 'danmachi riveria bell light novel'.
Well, Bell is obviously one of the most popular. He's the main character in the original series and in the fanfiction, his growth and adventures are always the focus. People like to read about how he overcomes new challenges in the game - like setting.
Another concept might be the introduction of new characters through the fanfiction's game - like world. Maybe a character who is a master strategist in the game and teams up with Bell. They could have different playstyles that complement each other, adding a new dynamic to Bell's adventures.