Genos was one of the newest additions to the Hero Association at the beginning of One Punch Man. Impressively, he managed to secure the 12th rank in the S-Class, which is the highest and most prestigious tier of the Hero Association. The class consists of some of the strongest and most popular heroes in the world.
However, Genos has been shown to get injured pretty easily during the majority of his battles in the One Punch Man series. As such, fans often question the validity of his ranking as the 12th S-Class hero, while some even draw comparisons to King, an ordinary citizen mistakenly viewed as one of the mightiest heroes in the world.
Examining Genos' strength as an S-Class hero in One Punch Man
After joining the Hero Association and undergoing a thorough evaluation, Genos was designated to the S-Class, which is the most prestigious tier in the organization. He went on to be known as the 'Demon Cyborg' after he became a professional hero.
On the other hand, Saitama, who's canonically the strongest character of the One Punch Man series, was placed in the C-Class since his physical strength could not be evaluated.
That said, Genos has proven to be an extremely strong and reliable character throughout the series and is far from the weakest hero in the S-Class.
At the beginning of the One Punch Man series, there were originally 17 heroes belonging to the S-Class. However, this number was reduced following the resignation of Child Emperor and Silver Fang. It was then that Genos acquired the 12th rank of the S-Class. He was among the lowest-ranked heroes of the prestigious class.
Despite his low rank, Genos outclasses several heroes who are ranked higher than him, mainly due to his ammunition, firepower, and excellent close-combat abilities. In fact, he constantly receives upgrades after each fight, which leads to him getting stronger as the story progresses.
While it's difficult to predict where exactly he would rank in terms of power, one can assume that he could outrank the likes of Flashy Flash and Pig God, who are both currently officially ranked higher than him.
In the world of One Punch Man, a hero's rank and class are considered to be more important than their individual strength. Their classes determine people's attitude towards them as well as their position in society.
While heroes belonging to the S-Class and A-Class are revered and praised by the people, those belonging to the lower tiers do not get much respect from their colleagues or the public.
However, a hero's rank is not solely based on their individual strength but rather a combination of their popularity, power, reputation, and aura. This is one of the many reasons why Saitama was considered to be weak by many, whereas King was hailed as one of the strongest heroes of the world despite being nothing more than an ordinary human.
Per the official rankings, the lowest ranked S-Class hero is Puri-Puri Prisoner. However, he has been shown to possess an incredible amount of strength and held his own against a Dragon-level monster, the Deep Sea King, albeit momentarily.
Therefore, King would technically be the weakest S-Class hero since he is simply an ordinary citizen with no powers or experience in fighting monsters. In fact, he achieved the fifth rank in the S-Class after being mistakenly credited for almost all of Saitama's achievements in the One Punch Man series.
It can be thereby concluded that Genos, aka the Demon Cyborg, is far above King in terms of power. While it might be up for debate, Puri-Puri Prisoner is, perhaps, the weakest S-Class hero after King.
That said, being the lowest-ranked S-Class hero is certainly nothing to be scoffed at, considering they are equivalent to an emergency army division and are much more powerful than the majority of the heroes in the Association.
Final Thoughts
Achieving a rank in the S-Class is no easy task for any hero in the One Punch Man series. The fact that Genos was able to accomplish the feat pretty early on in the series speaks volumes of his strength. While he may not be as strong as some of the other heroes above him, he tries his absolute best in all of his fights and never backs down, even in the face of death.