At first, it might be one of suspicion. Naruto would be wary of Kaguya's power and her past as a sort of villain. But as they face challenges together, they could start to respect each other. Naruto might see the good in Kaguya that was buried under her past actions, and Kaguya could come to admire Naruto's tenacity and his strong sense of justice.
Sasuke can also be involved in some cases. Since he and Naruto are often together in many situations, Sasuke's presence might add some complexity to the relationship between Kaguya and Naruto. For example, Sasuke might be suspicious of Kaguya's intentions towards Naruto at first.
Naruto's Rasengan combined with Hinata's Gentle Fist could create a really powerful attack. Maybe Naruto could infuse his Rasengan with Hinata's chakra control, allowing it to be more precise and targeted. And if Kaguya's powers were added to the mix, say her ability to create dimensions, they could use that to their advantage in battle. For example, they could trap enemies in a dimension and then attack them with their combined Naruto - Hinata attack.
Naruto's chakra and Kaguya's chakra are both very powerful but in different ways. Naruto's chakra is more about positive energy and his willpower, while Kaguya's is ancient and more raw. If they were to interact, Naruto's positive chakra might start to influence Kaguya's, perhaps making her more empathetic. For example, when they fight side by side, Naruto's chakra could boost Kaguya's attacks in a way that gives them a more moral or just - focused energy.
Kaguya can be a powerful and mysterious element in the crossover. She could be a catalyst for change. For example, her powers might attract the attention of the various factions in DxD, leading to conflicts or alliances.
Their interaction could be one of conflict at first. Naruto is used to fighting powerful foes, and Kaguya is no exception. He'd likely charge in with his Rasengan or some other jutsu, while Kaguya would use her otherworldly powers. However, as the story progresses, Naruto might start to realize that there's more to Kaguya than just being a villain. He might try to communicate with her, using his talk - no - jutsu. And Kaguya could be intrigued by Naruto's unwavering belief in his friends and the world, which is something she may have long forgotten in her isolation.
The most immediate consequence would be a huge power boost for Naruto. He'd likely gain abilities like teleportation, space - time manipulation, and extreme chakra control. This could make him a target for those who want that power. Also, it might affect his mental state as he tries to cope with the sudden influx of power and the knowledge that comes with Kaguya's abilities.
Well, it could change the perception of the origin of chakra in the Naruto universe. Since Kaguya was the first to possess chakra, her interaction with Naruto might reveal more secrets about chakra's true nature. Also, the political situation in the ninja world could be affected. With Kaguya's existence, different villages might form new pacts or rivalries depending on how they perceive her threat or potential power. Naruto would be in the middle of all this, trying to keep the peace and understand the implications of Kaguya's arrival.
One interesting plot idea could be that Kaguya is reborn in the modern Naruto world. She has no memories of her past at first. Naruto discovers her and senses a strange power within her. As she starts to regain her memories, she struggles between her old self and the new world she's in. Naruto has to decide whether to trust her or not.
A potential plot could be set in a future where the ninja world is facing an extinction - level threat. Scientists or ninja elders attempt a risky fusion of Naruto, Hinata and Kaguya as a last - ditch effort. The fused character has to quickly learn to control their powers and understand their new self. They might face internal struggles as the different personalities of Naruto, Hinata and Kaguya clash within them. Externally, they must battle a powerful enemy that has the ability to destroy the entire ninja world. This could lead to a story full of action, drama and self - exploration.