One possibility is that it was going to be a crossover where the Devil May Cry characters end up in the Naruto world. Imagine Dante showing up in Konoha and causing a stir. He could be mistaken for a powerful enemy at first, but then they realize he's there to help fight a common threat, like some new kind of demon - like entity that's causing chaos in the ninja world. The story could explore how the two different groups interact and combine their powers.
It might have been a more complex story where a character from an abandoned Naruto arc somehow gets linked to the Devil May Cry lore. For example, a character with a dark past in Naruto could be related to a demon in the Devil May Cry universe. The fanfiction could have delved into this connection, showing how the Naruto character's past experiences shape their actions in the Devil May Cry world. They could be on a quest for redemption or power, and the Devil May Cry setting provides a new and dangerous backdrop for this journey.
Well, it could have been about a character from Naruto ending up in the Devil May Cry universe. Maybe Naruto himself gets transported there and has to use his ninja skills to fight demons. He might learn new abilities from the Devil May Cry characters, like Dante's swordsmanship or Vergil's cool moves. And perhaps there would be some sort of conflict between the ninja way and the demon - hunting way of the Devil May Cry world.
Another reason might be that they faced some sort of writer's block. Coming up with new plot ideas, especially for a crossover as complex as Naruto and Devil May Cry, can be really challenging. They might have hit a point where they didn't know how to progress the story further. Or perhaps they received some negative feedback early on that discouraged them from continuing.
One possible plot is that there's a powerful demon in the Naruto universe that has a connection to the underworld of Devil May Cry. Naruto and his friends seek help from Dante and Vergil. Along the way, Naruto learns about the different types of demons in the Devil May Cry world and how to combat them using his chakra in new ways. The story could be filled with intense battles and character development as they all try to stop the demon's evil plan.
Well, one possible plot could be that in a strange crossover world, Naruto's chakra somehow connects with the demonic energy in the Devil May Cry universe. Lady and Trish, being the powerful demon hunters they are, initially see Naruto as a threat. But as they get to know him, they realize his noble intentions. Maybe Naruto helps them in a fight against a powerful new demon that is immune to their usual weapons and tactics. His unique abilities could be the key to victory, and during this adventure, a deep bond forms between them, not exactly a'mate' in the romantic sense at first, but more like comrades. As time passes, this bond could potentially develop into something more, with Naruto learning about their world and they learning about his ninja way.
The Naruto world has a rich lore with tailed beasts and different bloodlines. The Devil May Cry world has its own lore regarding demons and the underworld. In fanfictions that combine these two, the merging of these lores can result in really unique storylines. For example, a fanfiction could explore what would happen if a tailed beast was possessed by a powerful demon from the Devil May Cry world, and how the characters from both universes would deal with such a situation.
One possible plot could be Dante from Devil May Cry finding himself in the world of Bioshock. He might initially be confused by the strange environment full of splicers and Big Daddies. He could use his combat skills to fight off the threats while trying to figure out a way back to his own world. Maybe he teams up with a Little Sister, using his devilish powers to protect her from the various dangers in Rapture.
The plot could be centered around a mysterious portal that opens up in the Forest of Death, connecting it to the world of Devil May Cry. Characters from both universes are drawn into this new situation. The ninjas are confused by the demonic entities they encounter, while the Devil May Cry characters are intrigued by the concept of ninjutsu. They must work together to close the portal before the two worlds collide catastrophically.
Well, in a fanfiction like this, maybe Naruto is given the devil fruit as a gift from a mysterious being. However, he quickly realizes that it's affecting his chakra system in a negative way. So, he abandons it. Later, an enemy gets hold of the fruit and becomes extremely powerful. Naruto then has to use his ninja skills and the power of friendship to defeat this new foe.
One possible plot could be that Dante and Bayonetta are both drawn to a powerful demonic artifact that has the potential to either destroy or rule the underworld. They initially clash, thinking the other is after it for the wrong reasons. But as they face off against powerful demons sent to retrieve the artifact, they realize they need to work together. Dante's wild and carefree style combined with Bayonetta's sassy and powerful moves would make for some epic fight scenes as they fight their way through hordes of demons.
I'm not entirely sure as I haven't read it thoroughly. But generally, it might involve Dante's battles against demons in a dark and supernatural world.
Naruto's ability to create shadow clones would be very useful. He could send clones to scout out areas full of demons, or use them as distractions in battle. His rasengan could be a powerful close - range attack against demons. Also, his chakra control could potentially be used to enhance Devil May Cry weapons, like making a sword cut through tougher demon hides more easily.