Naruto himself is the most obvious one. Since it's a Naruto - related fanfic, he would likely be at the center of any crossovers with god - like entities. His strong will and desire to protect his village make him a prime candidate for interacting with powerful gods.
Well, characters like Jiraiya could be really interesting in a 'naruto crossover godlike fanfic'. He has a lot of knowledge about the ninja world and different powers, so his encounter with god - like beings would be full of potential for interesting stories. Tsunade too, as a powerful Hokage, could be involved. She could represent the Naruto world's power structure when dealing with these otherworldly god - like entities. And then there's Orochimaru, who is always seeking more power, so he would be very likely to get involved in any situation where there are god - like powers to be had.
Naruto himself is very likely to be involved. He's the main character of his series and his unique abilities like the Rasengan and shadow clones would make for great interactions. Sasuke is also a top candidate. His Sharingan and his dark past could create interesting storylines when combined with hero concepts. Sakura, with her medical ninjutsu and strength, could also be involved, perhaps teaming up with a hero who has a similar healing - based power.
Definitely Hinata. Her gentle yet strong - willed nature could be an interesting contrast when dealing with the often - mischievous yokai from Nurarihyon. Gaara too, as his own experiences with being an outcast and having a powerful force within him could have parallels in the Nurarihyon world where some yokai are feared or misunderstood. And Rock Lee, his determination and unique fighting style could bring a new dynamic to the interactions in the fanfic.
Definitely other Kamen Riders like Kamen Rider Kabuto. Their different powers and personalities would make for an exciting crossover. They could team up with Faiz to fight a common enemy or have a friendly rivalry.
Kakashi could also be involved. Maybe he's put in a difficult position where he can't save Naruto for some reason, like being under a powerful genjutsu or being blackmailed. This would create an interesting conflict as he's Naruto's teacher and mentor.
Naruto and Sasuke are very likely. Their contrasting personalities and styles make a clothes swap between them full of potential. It would be a great way to show their differences and similarities in a new light.
Gaara could also be part of the fanfic. Since he has his own unique abilities related to sand, there could be an interesting interaction between his powers and Naruto's summoned creatures. For example, Naruto could summon a water - based creature and they could team up with Gaara to fight an enemy that is strong against both sand and water.
Homer Simpson is very likely to be involved. He's the main character and his bumbling yet loveable nature can create a lot of comical situations in crossovers. For instance, if it's a crossover with 'The Flintstones', Homer would probably be trying to out - eat Fred Flintstone at the local diner.
Well, obviously Naruto himself is the central character. Sasuke could be involved as he has a complex relationship with Naruto. In a crossover, if Naruto is betrayed and ends up in the Dragon Ball universe, Vegeta might be a character he interacts with. Vegeta could initially see Naruto as a weakling but later come to respect his skills. Another character could be Luffy from One Piece. If Naruto is betrayed and crosses over to the One Piece world, Luffy would likely befriend him and help him out, seeing Naruto's situation as similar to his own crewmates' struggles.
Voldemort would also be a key character. His obsession with immortality and his actions that led to many deaths in the series are fundamental to the theme of life and death. In a crossover, he could be pitted against new threats or forces that have different views on death, which would make for an interesting story.