Harvey Dent, or Two - Face, is another favorite. His fall from grace and his split - personality concept offer a lot of room for exploration. Fanfiction can delve into his recovery attempts or his further descent into villainy.
Definitely Joker. He's such an iconic character in The Dark Knight universe, and when it comes to crossovers, his chaotic nature can create great interactions with characters from other franchises. For example, if he meets the Joker from the DC Animated Universe, it could be a really wild and unpredictable encounter.
Sonic, without a doubt, is the most crucial character. But in addition to him, characters like Silver can bring a different perspective. His ability to manipulate time in a way could be incorporated into the Black Knight story in unique ways. Also, Rouge. Her thieving skills and her relationships with other characters can be a great addition. And don't forget about the characters native to the Black Knight world, like King Arthur - like figures, who can add a touch of medieval fantasy to the fanfiction.
One of the most popular characters to include is the outcast. This character is already on the fringes of society and may have a special connection to the whispers because of it. They could be seen as an outsider looking in on the normal world that is being disrupted by the whispers. Another great character is the wise elder, who has heard tales of the whispers in their youth and can offer valuable advice. And a character with psychic abilities who can communicate with the source of the whispers in a different way than the others can also be very interesting to write about.
Batman is obviously a very popular choice. Writers often like to delve deeper into his psyche, especially after the events of 'The Dark Knight Rises'. They might explore his internal struggles with coming back to the role after a long break or his thoughts on how to better protect Gotham in the future.
Obviously, the Joker and Harley Quinn are the most popular. The Joker's chaotic and unpredictable nature makes for great story - telling. He can be the main source of conflict and drama. Harley Quinn, on the other hand, has a complex character. Her love for the Joker despite his abuse, and her own journey of self - discovery are very interesting to explore in fanfiction.
Batman is obviously one of the most popular. In fanfiction, we often see different takes on his character, like a more vulnerable Batman or an even more hardened version.
The Joker could also be a very popular character in these fanfictions. His chaotic and unpredictable nature can create intense and engaging storylines when paired with Raine. Their interactions could range from battles of wits to full - on physical confrontations.
Batman, of course, is essential as he is the Dark Knight. His brooding and strategic nature adds a lot of depth. Superman also makes a great contrast to Batman. Their different ideologies on how to use power can create interesting conflicts and collaborations. Wonder Woman is another great addition. Her warrior spirit and unique powers can bring a different dynamic, especially when she teams up with Batman for a mission.
Catwoman can also be a popular character to pair with Bane in fanfiction. Her own brand of chaos and thievery can interact in interesting ways with Bane's brute force and strategic mind. Also, Commissioner Gordon could be paired with Bane in a story where Gordon has to outwit Bane in a more cerebral battle, as opposed to the physical battles Batman has with him.
Crow Hogan is often a popular character to include. He's Yusei's friend and his presence can add more depth to the story. Another one could be Jack Atlas. His rivalry with Yusei and his strong personality make him a great addition. Also, Akiza Izinski might be included as she has her own powers and a connection to Yusei.