One-Punch Man introduces a world filled with superheroes battling monstrous threats, featuring a diverse array of characters, some of whom could challenge even My Hero Academia’s All Might.
Beyond just raw power, many of the show’s side characters stand out for their unique personalities and intriguing roles in the storyline.
Metal Knight fights with machines, but who controls the hero (Photo: One Punch Man/Madhouse)Since the series itself thrives on satire, numerous heroes possess peculiar quirks and eccentricities that add to their appeal. Some characters exist purely for comedic relief, while others contribute to the overarching sceneries in unexpected ways.
Metal Knight
Utilizing Iron Man-style advanced weaponry, Metal Knight demonstrates immense combat power, rivaling Genos with his cutting-edge technology. However, an intriguing twist reveals that this so-called hero is merely a remotely controlled drone, operated by an enigmatic figure from an undisclosed location.
His interactions with fellow heroes are defined by his cold and methodical approach, treating battles less as heroic endeavors and more as scientific experiments. This detachment makes him a figure of both respect and wariness among his peers.
Terrible Tornado
Among the most formidable Class-S heroes, Terrible Tornado ranks second within the association and wields immense psychic power. Like Saitama, she exhibits an indifferent attitude, largely due to her ability to dispatch foes with ease.
Unlike Saitama, however, she leans toward arrogance and impatience. In season one, she takes charge during the alien invasion, belittling her fellow heroes in the process. By season two, when forced to step in to protect her sister, her reaction suggests irritation rather than genuine concern.
Speed-o’-Sound Sonic
Neither a hero nor a traditional villain, Speed-o’-Sound Sonic exists as an unpredictable wildcard. His sole objective remains singular—defeating Saitama to reclaim his lost pride after suffering a humiliating defeat.
His capabilities are nothing to scoff at, as evidenced by his ability to keep up with Genos in combat using his incredible speed. By the end of season two, his desire for power leads him to consume a monster cell, hinting at a potential transformation that could take him to an even greater threat.
Suiryu
Each character in One-Punch Man has their own reason for seeking strength, and for Suiryu, it’s simply a means to a comfortable life. As a dominant force in the martial arts tournament, he exhibits a carefree attitude, though his overconfidence eventually leads to a humbling encounter with Saitama.
Their matchup proves entertaining, as Suiryu quickly realizes his attacks are useless. However, his role extends beyond the tournament, as he later stands against Goketsu when martial artists are tempted with monstrous power enhancements.
Watchdog Man
Watchdog Man, a peculiar Class-S hero, dons a full-body dog costume, presenting himself as more of a visual gag than a conventional hero. Despite his comical appearance, his abilities remain shrouded in mystery for much of the series, with only glimpses of him sitting atop piles of defeated monsters.
Not until Garou challenges him in season two does his true prowess become evident. Utilizing a unique four-legged fighting style, he effortlessly counters Garou’s attacks, proving too formidable for him to overcome. This leads Garou to incorporate Watchdog Man’s techniques into his own combat strategy.
Metal Bat
Sporting a pompadour and a delinquent-style jacket, Metal Bat embodies the classic image of a rebellious high school brawler. At first glance, his gimmick appears straightforward—he wields a metal bat and uses brute force to devastating effect, earning his Class-S ranking.
Season two reveals deeper layers to his character, showcasing his ability to grow stronger as he sustains more damage, attributing it to his “fighting spirit.” Additionally, his bond with his younger sister adds an emotional dimension, as he swears never to fight in her presence out of respect for her wishes.
Hellish Blizzard
Hellish Blizzard, the younger psychic sister, holds the top position in B-Class, wielding considerable esper abilities. While she operates as a registered hero, her true focus lies in maintaining her rank rather than embodying traditional heroism.
To secure her standing, she enforces her influence through intimidation, employing a group of subordinates to prevent others from surpassing her.
Despite her questionable motivations, she proves her worth in season two when she joins the fight against the Monster Association. However, even with her strength, she requires her older sister’s intervention to survive the battle.
Silver Fang
Comparable to a more serious version of Master Roshi from Dragon Ball Z, Silver Fang (also known as Bang) stands as one of the most skilled martial artists among the Class-S heroes. His elderly appearance contrasts sharply with his formidable combat abilities.
Terrible Tornado’s psychic power matches her towering arrogance (Photo: One Punch Man/Madhouse)In the first season, he takes on a mentor-like role, despite the irony of attempting to guide someone as overwhelmingly powerful as Saitama.
Season two introduces a more dramatic element, as he grapples with the reality that his former student, Garou, has turned into a villainous force. Despite his age, his martial arts expertise allows him to stand toe-to-toe with his wayward disciple.
King
Teased throughout the first season, King’s truth is finally revealed in season two—he is a fraud. His reputation as a Class-S hero stems from mere coincidences, as he always happens to be present after another hero has saved the day, inadvertently receiving credit for victories he never earned.
Even his supposed “King Engine” is nothing more than his heartbeat pounding in fear. Ironically, Saitama played a pivotal role in King’s unearned status, having once saved him from a monster attack. Over time, the two form an unlikely bond, bonding over video games.
Despite his lack of physical strength, King displays moments of genuine heroism by using his intelligence and quick thinking to go through dangerous situations.
Mumen Rider
Mumen Rider stands out as a compelling side character due to his stark contrast with Saitama. While Saitama yearns for a real challenge, Mumen Rider embodies the aim of heroism despite his physical limitations, prioritizing the well-being of others above all else.
One of the series’ most memorable moments occurs when he bravely confronts the Deep Sea King, knowing full well he stands no chance. As he falls, Saitama arrives to finish the battle, symbolizing a moment of mutual respect between the two.
In season two, Mumen Rider continues to uphold his principles, intervening when fellow heroes risk going too far and standing up against monsters even while injured. His unwavering dedication solidifies him as a true hero, regardless of his power level.