In certain comic arcs, the Joker is shown to have a brother. But it's not a common or consistent aspect across all Joker-related comics. Sometimes it depends on the specific writer's creative choices.
Well, often in fanfiction, Naruto's love for his brother can be depicted as a deep emotional bond. This might be different from the relationships he has in the original story. Maybe he has a brother who is in a difficult situation, and Naruto's love drives him to fight against all odds to save his brother. It could be a story full of heart - warming moments and intense emotions.
The Joker is usually depicted as a lone figure without a twin brother. This absence of a twin contributes to his solitary and unpredictable image in the comics.
If Naruto is a brother in this fanfiction, it would change the dynamic quite a bit. He might be more bossy in a brotherly way, making sure his 'siblings' in Team 7 are training hard and staying out of trouble. His relationship with Sasuke, for example, would become less of a rivalry and more of a brotherly competition to make each other better. And with Sakura, he could be more over - protective, which might annoy her at times but also make her feel secure.
Naruto might also be determined to change his brother's mind. He would keep showing his good side, like his kindness and his strong will to protect the village. He could think that by being a better person, his brother will eventually stop hating him. He may even go through some tough training to prove himself not only to his brother but also to the whole village. And in the process, he may face a lot of difficulties and rejections from his brother, but he won't give up easily.