Maybe even Gaara could be a sidekick. He has unique sand powers that could be useful in different ways. For example, his sand could detect hidden traps or substances that normal eyes can't see. Also, his own experiences as a leader and a fighter would give him a different perspective when it comes to solving mysteries.
Shikamaru would be an excellent choice too. He's known for his intelligence and strategic thinking. He could help Naruto piece together clues and come up with plans to catch the bad guys. His lazy - but actually very perceptive - nature would add an interesting dynamic to their detective team.
Sakura could be a great sidekick. She has medical skills which could come in handy during investigations, like when they need to analyze strange substances or heal victims of attacks. Also, she's strong and smart, able to hold her own in a fight if they encounter resistance.
A group of disgruntled former Stark Industries employees could become his sidekicks. They feel betrayed by Tony in some way, maybe due to layoffs or unfulfilled promises. So when he turns villain, they join him, using their skills to help him carry out his evil plans, like sabotaging other tech companies or stealing their research.
One possible sidekick could be Miranda. Her clumsy yet endearing personality would make for some interesting interactions with chibi Allen Walker. She could also use her time - reversing Innocence to get them out of some tight spots. Then there's Bookman. Bookman's vast knowledge could be invaluable to chibi Allen Walker. He could guide him on different missions and help him understand the deeper secrets of the exorcist world. Also, Krory could be a sidekick. His vampire - like abilities and his journey to control his bloodlust could be a source of both drama and friendship for chibi Allen Walker.
Misty could be another sidekick. She's strong - willed and has her own set of skills. She could use her water - based Pokemon to assist Ash in battles, especially against fire - type opponents. Plus, her knowledge of Pokemon and the world around them could be really helpful in their superhero adventures.
Batgirl is also an important sidekick. She has her own skills and storylines. She is a strong female character who helps Batman in his fight against crime in Gotham. Her presence also adds a different dynamic to the Batman universe.
He could share it with Hinata. Given their relationship, Naruto might transfer some of his chakra to Hinata to protect her during a dangerous situation. This would also strengthen their bond further in the fanfiction.
Well, one plot twist could be that Naruto discovers that the real villain is someone he trusted all along, like a respected elder in the village. Maybe this person has been secretly manipulating events to create chaos for their own gain.
Sasuke could be a major rival. Even if Naruto is a child genius, Sasuke's natural talent and his drive for revenge could put him in direct competition with Naruto. They might constantly try to outdo each other in training and in battles.
A new, unknown villain could be the cause. This villain might have a special power related to mind control or mental manipulation. They target Naruto because of his status as a hero in the ninja world. By making Naruto lose his mind, they could throw the entire ninja world into chaos.
It could be Orochimaru. He is known for his devious ways and might manipulate Naruto into believing false things about the ninja world.
I'm not sure specifically who the main characters are without reading it. But they could be young heroes or sidekicks with special powers.