Batman would definitely be a main character. He's the Joker's arch - nemesis, and when the Joker becomes a baby, Batman might be the one who first discovers him. He'd be in a moral dilemma about what to do with this baby version of his greatest enemy.
One common theme is the exploration of power. As a vampire, the Joker has enhanced physical and mental abilities, and fanfictions often play with how he uses this power for his own twisted games. For example, he might use his vampiric charm to manipulate people more easily.
If Batman becomes Joker in fanfiction, Gotham would be in chaos. Batman is the symbol of justice and order, while Joker represents chaos and anarchy. Without Batman to protect the city, criminals would run wild. And as the new 'Joker', Batman might use his intelligence and skills in a very different and dangerous way, perhaps creating more harm than good.
Well, it could be about the Joker somehow getting transformed into a baby. Maybe he retains some of his villainous traits even as a baby, causing chaos in a comical way. For example, he might still have that evil laugh and try to play pranks on the other characters in the story.
The plot could start with Naruto being disillusioned with the shinobi world. He might see the hypocrisy and the never - ending cycle of war. This leads him to embrace the Joker's ideology of chaos. He could start by targeting the political figures in the Hidden Leaf, causing unrest. His friends would be shocked and try to stop him, but he would be too far gone.
I'm just a person who likes reading novels, so I can't provide the content of the novel. I can only answer questions about language and knowledge. If you have any other questions, please feel free to ask me.
If Harry Potter becomes the Joker in fanfiction, he would probably start to question all the values he once held. The Joker is all about subverting order, so Harry might begin to undermine the Ministry of Magic and other institutions. He could use his knowledge of magic to play cruel pranks on people, not the innocent kind of pranks he used to do. His Gryffindor courage could be twisted into a reckless disregard for the safety of others.
If Naruto becomes like Joker in fanfiction, it would be a really strange and interesting transformation. Naruto is known for his positive and determined nature, while Joker is chaotic and unpredictable. Maybe Naruto would start to question the values of his village and act in more devious ways. His friends might be very confused and try to bring the old Naruto back.
If Percy Jackson becomes the Joker in fanfiction, it would be a really wild and unexpected transformation. The story could take a very dark turn. Percy, who is usually a heroic figure, would now have the chaotic and unpredictable nature of the Joker. His friends in the Percy Jackson universe might not recognize him, and he could start causing all sorts of mayhem in both the demigod world and the mortal world. Maybe he'd use his newfound Joker - like insanity to play cruel tricks on his former allies or enemies, blurring the lines between good and evil even more in the fanfiction world.
Well, one way it could work is if Naruto's world somehow got merged with the dark and chaotic world of the Joker. Maybe Naruto, after facing so much pain and loss in his own world, starts to adopt the Joker's nihilistic views. He could use his ninja skills in a more unhinged way, like the Joker uses his chaos-creating abilities.