One possible storyline could be exploring the immediate aftermath of Bruce's death. How does Terry McGinnis handle the loss? Another could be flashbacks to Bruce's final days, showing his last words of wisdom to Terry.
Sure was. Batman Beyond was indeed a comic that explored the adventures of a new Batman in a dystopian future. It had unique storylines and art styles that attracted many fans.
I'm not sure there are many common fanfictions specifically about Batman, Mr. Freeze and diarrhea. However, it could potentially be a very strange and comical take where maybe Mr. Freeze's cold powers accidentally cause some sort of gastrointestinal distress to Batman or a bystander in Gotham. But this is really a very odd and not so common concept in the Batman fanfiction world.
The story where Mr. Freeze tries to freeze Gotham City to create a new environment suitable for his frozen condition is also great. It shows his extreme measures and how he's willing to go to great lengths for his own survival and to fulfill his goals. Batman has to use his wits to stop him from turning Gotham into an iceberg.
Mr. Freeze's story in Batman Arkham Origins is quite interesting. He is a supervillain with a tragic backstory. His wife is ill, and he is desperate to find a cure. This drives his actions in the game. He uses his cryogenic technology to create various obstacles for Batman. He is a formidable foe, not just because of his weaponry but also his determination.
In this fanfic, perhaps Mr. Freeze's ice - making abilities have gotten out of control, and Batman has to race against time to thaw the ice before it causes a global catastrophe. He might enlist the help of other DC heroes.
In terms of Batman's growth, in the harem fanfiction, his personal relationships force him to reevaluate his loner - hero approach. He starts to rely on the members of his harem for emotional support and different kinds of help. This is a big change from the original where he was more self - reliant and solitary in his crime - fighting journey.
Robin, in all his incarnations, is also a popular character in fanfiction related to Batman. He represents the sidekick aspect and the growth and development that comes with it. In Batman Beyond, Commissioner Barbara Gordon also features prominently in some fanfictions. Her connection to the original Batman era and her role in the new one can be explored in interesting ways.