Mumen Rider could be an interesting main character choice. His unwavering sense of justice and his determination despite being a relatively weak hero could be the focus. In a daily life fanfiction, we could see how he trains, his interactions with civilians, and how he looks up to heroes like Saitama even though he may not be on the same power level.
Well, perhaps a plot where Saitama tries to teach Genos some really mundane daily skills, like grocery shopping but in a super - hero - ish way. For example, he shows Genos how to find the best deals on discounted monster - fighting gear while also picking up some eggs and milk.
Maybe a former villain who is reborn with a new moral compass. They could start using their villainous skills for good, which would make for an interesting main character as they navigate their new life in the world of One Punch Man, trying to make amends for their past deeds while also fighting new threats.
There's a possibility that it's a completely new entity from another dimension or realm. This character with the 'golden name' enters the One Punch Man world with a mission to save lives. They might have abilities that are far beyond what the regular characters in the One Punch Man universe possess. Their golden name could hold the key to some great power or knowledge that is necessary to save the world from a new and greater threat.
Saitama is the most prominent character in 'One Punch Man Hero Story'. He's the one with the amazing strength of defeating enemies with just one punch. Genos, a cyborg, is another main character. He admires Saitama and becomes his disciple. There are also other characters like King, who has a reputation of being a very powerful hero but in reality, he just has a knack for being in the right place at the right time. And there are heroes from the hero association like Tatsumaki, a very powerful esper.
Another possibility is that the main antagonist is a corrupted hero. This hero, who has turned to the dark side, sees Kombu Infinity as a threat to his new - found power and plans. He uses his knowledge of the hero association and his own powers to try and eliminate Kombu Infinity, all while trying to keep his true identity a secret from the other heroes.
It expands the universe by exploring the backstories of the characters more deeply. For example, we might learn more about the childhood of characters like King. It also creates new scenarios for the heroes to face, like battles in different dimensions. This gives more depth to the world of One Punch Man.
Genos is also a favorite. Fanfiction authors might develop his relationship with Saitama further. For example, they could write about how Genos becomes even more determined to be like Saitama, or how he protects Saitama from threats that Saitama might not even consider serious. His backstory as a cyborg and his quest for revenge are also rich areas for exploration.
Often, original characters who are strong but also have a complex backstory are popular. For example, a character who was once a villain but turned to the side of the heroes for a very personal reason. Their struggle between their past and their new identity as a hero can be really engaging.
Genos would also be a great crossover character. His robotic nature and his unwavering loyalty to Saitama could bring a new dynamic to the My Hero Academia universe. He could potentially form a friendship with Iida, as they both have a sense of duty and order. Also, his advanced technology could be of great interest to the support teams and scientists in the My Hero Academia world.
Ned could be the main character in an alternate ending. He could find a way to hack into the Vulture's technology and disable his weapons. For example, while Spider - Man is busy in the physical fight, Ned uses his tech - savvy skills to disrupt the Vulture's flight systems, giving Spider - Man an edge in the battle.