Sure. A lot of fanfiction writers are drawn to the dynamic between Dazai and Chuuya. Check out Wattpad as well. Some stories there might have a unique take on a fem Chuuya's relationship with Dazai. It could be a story where they start as enemies but gradually develop feelings for each other, or perhaps a story set in an alternate universe where their relationship takes a completely different turn.
One common theme is the 'opposites attract' idea. Dazai is often portrayed as a carefree and somewhat nihilistic character, while fem Chuuya can be strong - willed and fiery. Their clashing personalities draw them together in many stories. Another theme is the exploration of their shared past in the mafia. Writers often use this background to create tension and emotional depth in their relationship.
Chuuya is not dead in the manga. The author has kept him alive to drive the story forward and create interesting developments. His presence adds a lot of excitement and intrigue to the plot.
Most BSD light novels often have complex characters. Since they are based on literary figures, they bring in the depth and complexity of those original personas. For example, a character might have the same traits as a famous writer but with a unique twist for the BSD universe.
Fem Harry might be heartbroken. She could initially try to win Edward back, using her magical abilities in creative ways. For example, she might create a magical memory of their time together to show Edward what they had was special.
Chuuya is a popular character. In chuuya and oc fanfiction, the original character (oc) often interacts with Chuuya in unique ways. It could be a story of adventure where the oc teams up with Chuuya to face various challenges. For example, they might battle against powerful enemies in a fictional city. This type of fanfiction allows fans to explore different relationships and storylines that are not part of the original canon.