Another idea is that Naruto, curious about other powerful beings, uses a jutsu to travel to the One Punch Man universe. There, he would be amazed by Saitama's strength. Naruto could try to learn from Saitama how to be so effortlessly strong, but Saitama would probably just shrug it off and say there's no special trick. They could team up to fight some of the monsters in Saitama's world, with Naruto using his ninjutsu and Saitama just punching things away.
One interesting concept could be the combination of One Punch Man's overpowered characters with other universes' power systems. For example, if Saitama were to enter the Dragon Ball universe, how would his 'one - punch' ability interact with ki - based powers? It would create a really unique dynamic where his seemingly unbeatable strength might be challenged in new ways.
Saitama is by far the most popular. His unique power of being able to defeat any opponent with one punch makes him a fascinating character to insert into other universes. Whether it's facing off against powerful foes in Naruto's ninja world or the superpowered individuals in My Hero Academia, his presence always shakes things up.
One possible plot could be that Saitama somehow ends up in the Naruto universe. He might be mistaken for a very powerful shinobi at first. Naruto, being Naruto, would probably be curious about Saitama's strength and try to befriend him. They could team up to face a new, extremely powerful enemy that neither universe has seen before, like a super - strong demon that can absorb chakra and is also incredibly durable like the monsters in One Punch Man.
One popular storyline could be Saitama getting transported to a different universe full of harem anime characters. He might then have to deal with the various personalities and powers of these characters while still being his overpowered self. Another could be the harem characters being brought into the One Punch Man world and how they adapt to its unique setting and Saitama's laid - back attitude. There could also be a story where a villain tries to use the harem characters to distract Saitama from saving the world, but of course, Saitama is unfazed.
Well, it could be about Saitama getting teleported into the Marvel universe. Maybe he'd start by accidentally punching a low - level villain really hard and causing a huge commotion. The Avengers might initially see him as a threat, but then realize he's just a super - strong, bald hero who just wants to fight strong opponents. He could team up with them to take on Thanos or some other big baddie.
Saitama and Naruto would have a rather comical interaction. Naruto is very talkative and enthusiastic, always ready to make friends. Saitama is the opposite, very laid - back and not overly expressive. Naruto would probably be constantly trying to engage Saitama in conversations about power and heroism, while Saitama would just be like 'yeah, whatever'. But when it comes to fighting together, Naruto's quick thinking and Saitama's brute force would complement each other well.
Saitama is obviously one of the most common characters since it's a One Punch Man crossover. Genos is also often included as he is Saitama's disciple. From the harem side, characters like Asuna from Sword Art Online might appear. She's a popular and strong female character. Another could be Rem from Re:Zero. Her quiet yet loyal personality could make for an interesting addition to the story. And of course, there could be characters like Erza Scarlet from Fairy Tail, with her powerful magic and tough - girl attitude.
It would be a wild crossover. The art styles of the two series are different, but in fanfiction, that could add to the charm. Dragon Ball Z has its more detailed and anime - esque style, while One Punch Man has a simpler yet impactful look. In the story, the characters could visit each other's worlds. Goku could explore the city where Saitama lives and be baffled by the normalcy of it all compared to his battles against Frieza and Cell. Saitama could also be introduced to the Dragon Balls and their wish - granting powers, which might pique his interest.
It's a tough call. Goku has the ability to keep getting stronger through training and achieving new forms like Ultra Instinct. However, Saitama has shown that he can defeat any opponent with one punch so far. But Goku's powers are more defined in terms of levels and growth potential. So, it's hard to say who would be the strongest in a crossover. It could depend on the situation and how the writer wants to portray their encounter.