There could also be original characters created specifically for the fanfiction. These characters could be used to further the plot, perhaps as new villains or as helpers for Naruto and Harley. For instance, a ninja who has some connection to Harley's past in the new combined universe of Naruto and DC.
In addition to the Joker, Harley, and their baby, there could also be other characters from the DC universe making appearances. For instance, Batman might show up as he is always on the lookout for the Joker's misdeeds. He could be a threat to the family unit in the fanfiction, or perhaps an unexpected ally in some situations. Also, other villains like Poison Ivy, who is Harley's friend, could play a role. Maybe she helps Harley take care of the baby or gives advice on how to deal with the Joker's wild behavior.
The main characters are obviously The Joker and Harley Quinn. The Joker is the infamous criminal mastermind in Gotham City, known for his chaos and unpredictability. Harley Quinn was once a psychiatrist named Dr. Harleen Quinzel who became infatuated with The Joker during her work at Arkham Asylum and then transformed into his partner in crime.
Well, obviously the main characters are Harley Keener and Peter Parker. Harley is known for his intelligence and engineering skills, especially after his interactions with Tony Stark. Peter Parker, of course, is Spider - Man, with his superhuman strength, speed, and that all - important spider - sense.
The main characters are, of course, the Joker and Harley Quinn. The Joker is a chaotic and unpredictable criminal, known for his maniacal laughter and disregard for human life. Harley Quinn was originally a psychiatrist named Harleen Quinzel who fell in love with the Joker during her attempts to treat him, and then she became his partner in crime.
In some fanfictions, Harley could be paired with new original characters created by the author. These new characters could be trainers who are either inspired by Harley or are trying to stop his more devious plans in the Pokemon contest circuit.
Obviously, Harley would be one of the main characters as she is replacing Peter. And characters like Aunt May could still be in the story. She might be a bit confused at first about this new person in Peter's place.
Obviously, Batman and Harley Quinn are the main characters. Batman is the dark knight, always brooding and focused on justice. Harley Quinn, on the other hand, is the wild and crazy ex - sidekick of the Joker.
The main characters are clearly Harley and Peter. Harley is the one making the call, and Peter is the recipient of the call. They are likely to be students in the same class or school.
It could be someone who wants to use Naruto's unique heritage against him. Maybe a villain from the Naruto universe who sees Naruto's connection to Harley Quinn as a weakness. For example, Orochimaru might want to capture Naruto to study his strange combination of powers.
The main character is, of course, Harley Quinn herself, also known as Harleen Quinzel. And then there's the Joker, who plays a huge role in her transformation. Poison Ivy is also an important character in Harley's story. They have a friendship, and Ivy often helps Harley out in various situations.