However, it could also be Naruto himself. But in this alternate reality, he could have a different form of the Nine - Tails' power. Instead of just being able to use the Nine - Tails' chakra, he could merge with it completely, becoming a being of pure energy with unlimited power.
Sasuke is often still very popular in alternate reality fanfiction. His cool and brooding nature can be explored in different settings. Naruto himself is also a common favorite as writers love to put him in new and strange situations. And Kakashi is popular too, his mysterious past and badass skills are always interesting to play around with in different realities.
It could be Naruto if he manages to master a blade that enhances his already strong abilities. His chakra reserve is huge, and with a blade that multiplies his power, he would be extremely formidable.
I think Doomguy could also be a top contender. His experience in fighting demons, his arsenal of powerful weapons, and his unwavering determination would make him a strong character in the Naruto - Doom crossover. He might not have chakra, but his combat skills are top - notch. If he were to learn some basic ninja techniques, he could become even more powerful.
Arceus would likely be the most powerful in terms of pure Pokemon power. It's a god - like Pokemon with the ability to create the entire Pokemon universe. However, if we consider Naruto characters as well, Naruto in his Six Paths Sage Mode could be extremely powerful. He has access to vast amounts of chakra and can perform incredibly powerful jutsus. If he were to team up with Arceus, they would be an unbeatable force.
It could be a character who has a combination of the rarest and most powerful bloodlines. Maybe someone with the Rinnegan along with the Kekkei Genkai of the Kaguya clan. The Rinnegan gives access to a wide range of powerful abilities, and the Kaguya - like powers would add even more strength in terms of physical abilities and unique jutsu.
It could be Naruto if he masters Fairy Tail magic. His already - powerful chakra reserves combined with magic could make him extremely formidable. He could use his Rasengan, for example, and infuse it with magic to create a much more destructive attack.
Perhaps in this alternate reality, there are no ninja villages at all. People live in a more unified world, but they face a new and powerful enemy that Naruto has to help fight. He would have to adapt his skills and learn new ways of combat that are unique to this world.
He could meet an alternate version of himself. This Naruto might have made different choices in life, like choosing not to pursue being a Hokage. It would be interesting to see how they interact.
There were many powerful characters in Naruto, and it was difficult to determine which one was the strongest. Every character had their own unique skills and characteristics that could play an important role in different battles. For example, Xiao Li was one of the strongest ninjas in Naruto. He had excellent physical skills and combat techniques, and could easily deal with all kinds of complicated battles. In addition, Uzumaki Naruto was also a very powerful character. He had the powerful strength of a nine-tailed beast and could use all kinds of powerful ninjutsu. Therefore, it was difficult to determine which character was the most powerful. Every character had its own unique charm and strength.
It would probably be Naruto if he's in his godlike state. With his vast chakra reserves and powerful jutsus, he could overpower most characters in the My Hero Academia world. His ability to create countless shadow clones and use techniques like the Rasengan or even more advanced forms would make him a formidable force.