There are also characters like Hestia. She is Bell's goddess. And Ais Wallenstein, a powerful swordswoman who Bell has a crush on. These characters play important roles in the 'dungeon danmachi light novel' as they are involved in various adventures, relationships, and the overall development of the story.
One way is through their experiences in the dungeon. For example, if an adventurer faces a near - death experience from a powerful monster, it could make them more cautious or more determined to get stronger. Another way is through interactions with other adventurers. They might learn new skills or ways of thinking from their comrades.
One idea could be an adventurer who discovers a hidden part of the dungeon that has a different set of rules. For example, instead of monsters attacking on sight, they have to solve puzzles to progress further. Another could be an adventurer who forms an unlikely alliance with a group of monsters in the dungeon to survive against a more powerful common enemy.
One of the great Danmachi fanfics is 'A Different Perspective'. It offers a fresh take on the characters and their relationships within the Danmachi universe. The story delves deeper into the backstories of some minor characters and makes them more significant. Another good one is 'The Unseen Adventures'. It takes the characters on new quests that are not in the original story, adding more excitement and mystery.