Another plot could be that the demon overlord is actually a misunderstood being. Naruto, with his big heart, tries to make peace with him. But there are forces on both sides that oppose this peace - making, leading to a complex and exciting story full of political intrigue and battles.
One idea could be that the demon overlord has a hidden past with Naruto's family. Maybe he was once an ally but was betrayed, and now he's back for revenge while Naruto tries to understand the truth.
One idea could be that Ainz Ooal Gown somehow ends up in the Naruto world. He could start by trying to understand the new world's power system. Maybe he'd initially be mistaken for a powerful jutsu user or a new type of tailed beast. Another plot could involve Naruto's friends being curious about Ainz's undead minions and trying to befriend them, while Ainz is cautious as he doesn't fully trust the inhabitants of this strange new world.
A really interesting plot could be that Naruto, as a demon, is wrongly accused of a series of attacks in the ninja world. He has to prove his innocence while also dealing with the prejudice and fear that his demon form instills in others. He might have to discover a way to temporarily suppress his demon form to gain the trust of those around him.
One idea could be that Naruto is somehow transported to the Overlord world and his unique abilities draw the attention of various female characters, leading to a harem situation. Maybe his ninjutsu skills are seen as a form of magic there.
One idea could be Naruto getting trapped in the demon world and having to form alliances with different demon clans to find his way back. He could learn unique demon jutsus during his time there.
Well, perhaps Demon Naruto has some sort of special connection to Kushina that is related to his demonic powers. For example, her Uzumaki bloodline might be the key to controlling or understanding his demonic side better. And they could go on a journey to discover the secrets of his powers together.
One idea could be that the demon prince has a hidden power that only Naruto can unlock. This power could be related to an ancient prophecy. Another could be that the demon prince is actually a misunderstood being and Naruto is the first to see his true nature. Maybe they team up to fight a common enemy that threatens both the human and demon worlds.
One plot idea could be that the Demon Queen is initially an enemy but Naruto, with his talk - no - jutsu, tries to understand her motives. Maybe she has a tragic past that led her to be a 'demon queen' and Naruto wants to help her change. Another could be that they are forced to team up against a greater evil that threatens both the ninja world and the demon realm. For example, an ancient dark force that wants to enslave both humans and demons.
Well, a plot could involve a young fox demon who is trying to find its place in the Naruto universe. It might start out as a mischievous character, causing small troubles in the Hidden Leaf Village. But as the story progresses, it discovers a connection to an ancient prophecy related to Naruto. This could lead to them teaming up and using the fox demon's unique powers, such as shape - shifting and illusions, to overcome challenges. Maybe the fox demon has a tragic backstory that Naruto helps it come to terms with, forging a deep bond between them.
One interesting plot could be exploring the backstories of the minor characters in the Overlord game world. For example, the lives of the villagers who interact with the powerful overlord character.
Perhaps a plot where an enemy targets Hinata to get to Naruto and the demon fox within him. Naruto then has to go on a journey to rescue her, all the while facing his inner demons, literally. Along the way, they could discover new things about their relationship and their own powers.