It could be another god - like being who is jealous of the female character's powers or her influence in the Naruto universe. This antagonist could be from the same realm as the female character but has different motives. He or she might want to use the chaos in the Naruto world to gain more power for themselves, and the female character stands in their way.
There could be a powerful ninja from one of the major clans who feels that the godlike female character is disrupting the natural order of the ninja world. This ninja could be very traditional and see her as an abomination or a dangerous foreign element. He or she might gather a group of like - minded ninjas to oppose the female character and try to drive her out of the Naruto world.
One potential crossover character could be Goku from Dragon Ball. Since Naruto has godlike powers in this scenario, a meeting with Goku, who also has superhuman strength and abilities, would be very interesting. They could have a friendly sparring match or team up against a common enemy.
Maybe an ancient being that was sealed away long ago in the RWBY world but has now been awakened by Naruto's arrival. This being, with its own set of dark powers, sees Naruto as a threat to its plans of domination. It starts to create chaos, summoning Grimm in large numbers and using some form of corrupted chakra - like energy to attack. The RWBY characters and Naruto would have to put aside their differences and combine their skills to defeat this powerful foe.
It could be one of the powerful vampires from Twilight. For instance, if they see Naruto's 'godlike' abilities as a threat to their way of life or power structure, they might oppose him. Aro, with his mind - reading ability and his ambition to control the vampire world, could be a likely candidate.
In a crossover with Fairy Tail, Lucy could be part of Naruto's harem. She is strong - willed and might be attracted to Naruto's godlike power and his kind heart. Also, from the Naruto universe, Hinata would surely be in the harem as she has always had feelings for Naruto.
He could interact with Ichigo from Bleach. Since Naruto is in a godlike state, their encounter would be really intense. Ichigo might be both in awe and on guard against Naruto's overwhelming power.
Maybe an evil scientist from the Lab Rats' world who has heard of Naruto's godlike powers and wants to harness them for his own experiments. He could create powerful robotic minions to fight Naruto and the Lab Rats. This scientist could be jealous of the Lab Rats' abilities and see Naruto as a new source of power to take over both worlds.
Another potential character is Harry Potter. His wizarding skills and knowledge of magic could be a contrast to Naruto's ninja abilities. Imagine Naruto in Hogwarts, learning about magic while also showing off his ninja moves. They could also face a threat together, like a dark wizard who is trying to use both magic and chakra for evil purposes.
Maybe Naruto from Naruto could be a crossover character. His ninja skills and Ichigo's combat abilities could create some unique fight scenes. Also, their different ideologies about friendship and power could lead to some great character interactions.
One potential character could be Naruto from the Naruto series. His ninja skills and strong will could create an interesting dynamic with 'godlike gon'. Another could be Goku from Dragon Ball. The comparison of their power levels and fighting styles would be really cool. Also, maybe Light Yagami from Death Note. The clash between 'godlike gon's sense of justice and Light's more morally ambiguous actions would make for an exciting story.
If it's a crossover with the One Piece world, Blackbeard could be a potential bad guy. His ability to steal Devil Fruit powers and his ambition to become Pirate King could lead to a clash with Gohan. Gohan's pure - hearted nature would be in opposition to Blackbeard's more devious ways, and their battle could be epic, with Gohan's ki powers against Blackbeard's dark powers.