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.
Genos from One Punch Man himself would be great. He could be the one who tries to explain Saitama's power to the characters from the other crossover universe. For example, in a crossover with Attack on Titan, Genos could be the one to tell the Survey Corps about Saitama's invincibility as they face the Titans.
One idea could be a crossover with Dragon Ball. Saitama could participate in the World Martial Arts Tournament and effortlessly defeat all the opponents, creating a hilarious situation. His nonchalant attitude would contrast sharply with the intense and competitive nature of the Dragon Ball characters.
Well, often a plot point is the culture shock. For example, Saitama being in RWBY's world and not understanding things like Dust or the Grimm. It's funny to see how he just approaches everything with his 'one - punch' mindset. Another is the power - level differences. RWBY characters have their own set of powers which are quite different from Saitama's extreme strength, and seeing how they interact in battles or training is really engaging.
There's 'Saitama in Remnant' which is also a popular one. In this fanfic, Saitama finds himself in the RWBY world. His overpowered abilities create a lot of chaos and also some hilarious moments as he tries to understand the different rules and threats in Remnant. It also has some great fight scenes where his simple punch causes massive destruction in the RWBY setting.
One idea could be that Naruto and Saitama somehow end up in a shared dimension where they have to team up to defeat a common enemy. For example, a powerful demon from Naruto's world that has the ability to regenerate like some of the monsters in One Punch Man's world. Another plot could involve Naruto learning Saitama's training regime and trying to incorporate it into his own ninja training, while Saitama is intrigued by Naruto's chakra system and tries to figure out if he can use it to make his punches even more powerful.
Well, Naruto's shadow clone jutsu could be really useful in a fight alongside Saitama. The clones could distract enemies while Saitama gets in a powerful punch. And Saitama's super strength could help Naruto in situations where brute force is needed more than ninjutsu. For example, if they had to break through a really thick and magically reinforced wall.
Humor is also a big theme. Since Saitama is such a non -chalant and often deadpan character, his interactions with characters from other universes tend to be really funny. In a crossover with Pokémon, for instance, his reaction to the cute but sometimes powerful Pokémon is both humorous and unexpected.
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.