Well, one possibility could be that Naruto, being the son of Darkseid, has to struggle with his dual nature. He might have the powerful abilities of Darkseid like Omega Beams but also the kind heart of Naruto. He could be in a constant battle within himself to decide whether to use his powers for domination like Darkseid or for protection like he always did in the Naruto world.
The story might start with Naruto growing up in the Naruto universe not knowing his true parentage. Once he discovers he's the son of Darkseid, he's thrust into a whole new world of power and politics. He may have to face off against other powerful beings from Darkseid's realm who want to either use him or destroy him. Meanwhile, he's also trying to keep his friends and the Hidden Villages safe from this new threat that his existence has brought.
One possible plot could be that Harry discovers his true parentage as the son of Darkseid. He might struggle with his newfound identity and the dark powers within him. He could be torn between the wizarding world he grew up in and the dark influence of his father. This could lead to him trying to find a way to use his powers for good, or he might be tempted to embrace the dark side at times.
His friends from the Naruto world like Sasuke and Sakura could be his allies. They've known him for a long time and would likely stand by him even with his new heritage. Also, characters like Batman from the DC universe might become his allies. Batman is known for seeing the good in people and might recognize that Naruto is different from Darkseid.
One possible plot for this fanfiction could be that Naruto, as Darkseid's brother, is sent to the Naruto universe as a sort of experiment or exile. He has to adapt to the world of ninjas, hiding his true origin. As he becomes a great ninja, his connection to Darkseid starts to surface. The Akatsuki could be interested in his powers related to Darkseid. Naruto then has to fight against the Akatsuki while also trying to figure out how to deal with his brother. He might try to find a way to use his Naruto - like positive attitude to change Darkseid's evil ways.
One possible plot could be that Darkseid somehow discovers the wizarding world. Harry Potter, being the central figure, might be targeted by Darkseid. Darkseid could see Harry as a potential threat or a tool for his power - hungry plans. Harry, on the other hand, would have to use his magic in ways he never thought before to fight against Darkseid's forces, which could include his minions from the DC universe.
One possible storyline could be that Naruto, intrigued by Darkseid's power, tries to find a way to incorporate some of Darkseid's dark energy into his own jutsu. He might start to study the nature of Darkseid's power in secret, causing his friends to become suspicious of his new and somewhat menacing behavior.
Well, it could be about Naruto having some special powers or abilities inherited from Deathwing. Maybe he has a dark side that he has to struggle with due to this connection. For example, he might have enhanced strength or the ability to control certain elements in a more menacing way compared to his normal skills in the Naruto universe.
Well, it could be about Naruto having the powers of Shukaku in addition to his own. Maybe he has to learn to control this new power source and face new enemies who are after his unique abilities.
In this 'naruto son of joker fanfiction', perhaps Naruto discovers his relation to the Joker later in life. This could lead to a whole new set of challenges. He might struggle with his identity, as he is known for his heroic nature in the original Naruto series. His friends could be confused or even a bit scared of him at first. And he would have to find a way to balance his new - found heritage with his existing values.
Well, it could be about Naruto having some sort of apocalyptic power since he's the'son of doomsday'. Maybe he has to struggle with controlling this power that is related to destruction. And he might face enemies who either fear or want to use this power for their own evil purposes.
In this fanfiction, it may be that Naruto's mother was actually Mileena in some sort of alternate universe. Naruto then has to deal with the political implications of being related to Mileena in a world that may not be friendly towards her. He could also try to use his new - found identity to bring peace between different factions, using his understanding of both the ninja world and Mileena's world.