As I said before, without more details, it's hard to determine who Bart Man is. He could be anyone from an ordinary guy with an interesting life to a fictional superhero - type character.
I'm not sure who Bart specifically is in this context. He could be just a fictional character created for the purpose of this scary story.
The name 'Bart Man' is rather ambiguous. It could refer to a character in a children's story, where he might go on adventures in a magical land. He could be making friends with talking animals, solving mysteries, and learning valuable life lessons. However, until we know more about the origin or context of 'Bart Man', we can't really give a definite story.
There might be a 'Black Bart' in a Christmas story that is unique to a certain region or a self - created story. It could be a character with a dark or mysterious past who has some sort of encounter during the Christmas season. Maybe he's a villain who has a change of heart during Christmas, but without more context it's hard to say for sure.
I'm not sure if there is a specific 'Bart Simpson Ladird Man' fanfic available. There are countless fanfics out there, but this particular combination might be quite rare or might not exist at all. You could try searching on some large fanfic platforms, but don't get your hopes up too much.
I'm not sure who played Black Bart. You might want to check reliable movie databases or reviews for the exact actor.
Homer is a great character to include. His clueless yet loveable nature can add a lot of humor. For example, when he tries to understand Bart's latest scheme. Lisa can also be interesting as she is the intelligent and moral compass of the family. And Milhouse, Bart's best friend, can bring in the element of loyalty and shared mischief.
One possible plot could be that Bart Simpson somehow stumbles into the world of Ladird Man. Maybe he's on one of his misadventures and a portal opens up. He then has to team up with Ladird Man to solve a mystery that threatens both their worlds.
There could be a girl from a rival school in Springfield. She comes to Springfield Elementary for some event and Bart is instantly intrigued by her confidence and the way she stands up to the Springfield bullies. This could lead to the start of their love story as they get to know each other better.
Homer could be involved. Since Homer loves food himself, he might either encourage Bart's new eating habits that lead to weight gain, or he could be the one trying to help Bart get back in shape. Marge would also be a key character. She would likely be concerned about Bart's weight gain and try to get him to eat healthier, constantly nagging him to stop eating junk. Lisa could also play a role. She might be initially teasing Bart about his weight gain but then feel bad and try to find a scientific way to help him lose the extra pounds.
The main characters are Bart and Cindy, as the title 'bart and cindy fanfic' suggests.