Summary
As far as the idea of an invincible superhero goes,One Punch Man’sSaitama is among the few truly indisputable examples, withMy Hero Academia’sAll Might, perhaps coming a close second.Both characters have relatively similar abilities, and the true extent of their strength is practically impossible to quantify.
However, given that the heroes in bothOne Punch ManandMy Hero Academiaare known to hone their abilities and develop means to overcome their limitations, it is not too much ofa stretch to imagine certain charactersgiving All Might a run for his money. From this angle, here are a few characters fromOne Punch Manwho could challengeMy Hero Academia’sAll Might in a fight.

Anime Debut
One Punch Man Episode #7
Just like Saitama and All Might,the actual extent of Metal Knight’s abilitiesis still yet to be ascertained, even for the Hero Association who manage all pro heroes in the world ofOne Punch Man. Another reason behind the threat posed by Metal Knight — whose real identity is Dr. Bofoi — stems from the fact that he remotely operates his arsenal of combat robots and weaponry.
This effectively allows him to take on powerful opponents without any real risk to his own life, which could prove vital in a battle of endurance with someone as incredibly strong as All Might. Moreover, Dr. Bofoi’s advanced intellect, tactical knowledge, and ability to devise complex countermeasures against his adversaries would be an ideal match for All Might, even if the “Symbol of Peace” in his prime may have had more raw power at his disposal.

Widely viewed as one of the two greatest martial artists in the world alongside his elder brother Bomb, Silver Fang — whose real name is Bang — wasformerly the third-ranked S-Class hero, which speaks volumes of how strong he is. Even though his raw strength and durability may be slightly lower than All Might’s own, Silver Fang’s greatest strength lies in his signature martial arts fighting style.
Described as the perfect blend of offense and defense by Genos, Silver Fang’s Water Stream Rock Smashing Fist focuses on redirecting an opponent’s attacks by emulating torrential and undulating forces. It is exceptionally effective against humanoid opponents of a size comparable to the user, and it allows Silver Fang to outperform many high-ranked S-Class heroes despite being past his physical prime. Unlike others who might face All Might head on, Silver Fang’s capacity to use his opponent’s strength against them could really make a difference in a fight against All Might, even if his chances of victory are slim.

One Punch Man Episode #6
As the most powerful esper inOne Punch Man, Tatsumaki’spsychokinetic abilities far exceed thoseof any other character, to the point where she can lift entire cities and deform them all on her own. Regarded as one of the Hero Association’s ultimate weapons, she is the second-ranked S-Class Hero, wielding strength that is leagues beyond the majority of her peers.
Capable of taking on multiple Dragon-level Mysterious Beings, Tatsumaki’s wide range of effectiveness and ability to redirect attacks would be invaluable against All Might’s overwhelming physical strength. Her intelligence, speed, reflexes, and durability are also comparable to All Might’s own, and any fight between them would be very closely fought. Tatsumaki’s pride in her own strength has also led her to push past her limits and unlock new levels of her power at times, which could also play a part in a conflict of this scale.

One Punch Man Episode #24
The mysteriousfirst-ranked S-Class Hero who answersonly to a select few members of the Hero Association, Blast’s power is beyond compare, to the point where he could potentially single-handedly take on most of the S-Class heroes. The true scope of his abilities is yet to be ascertained, especially since he has been shown using some form of psychic or mind-reading powers, in addition to his monumental strength.
Blast’s power to manipulate space-time and gravitational forces is one of the main reasons why he is the only S-Class hero who can take on God. He has been shown holding his own against the likes of Cosmic Garou and easily repelling the attacks of high-ranking S-Class heroes such as Flashy Flash without being even a little fazed. All this ties into why he could pose a real threat to All Might in a fight, since his powers can bend the fabric of reality itself.

One Punch Man Episode #1
Byvirtue of being the titular protagonistofOne Punch Man, Saitama is undoubtedly the strongest character in the series so far, even if his ranking in the Hero Association may not reflect it. Having broken his natural limiter, Saitama’s power can adapt and evolve without any upper ceiling, to the point where his strength and invulnerability have been described as defying all reason.
His feats are as impressive as they are numerous, ranging from taking a head-on gamma-ray burst from Cosmic Fear Mode Garou to delivering punches that could destroy the entire earth or blowing away half of Jupiter’s gases with only a sneeze. Moreover, Saitama can survive in outer space or on inhospitable extraterrestrial worlds for limited periods, and even molten lava appears to have no effect on him. Despite the lack of refinement in his fighting style, Saitama is extremely effective with his limited skill sets, and is perhaps the only person on this list who could perhaps defeat All Might on his day.
