Amai Mask, also known by his real name Handsome Kamen Amai Mask, is an A-Class Hero in One Punch Man. He is not only a hero but also a popular celebrity. His character is often shown to be charismatic, although he has a deep secret that redefines how we perceive strength and power in the One Punch Man universe.
In the series, Amai Mask’s position is in A-Class, just below the elite S-Class. And this is not because he cannot advance to a higher ranking. Interestingly, he does not want undeserving heroes to level up.
His true powers as a hero are fully visible during his battle against the Dark Matter Thieves and especially in the Monster Association Arc. Amai Mask has shown his brute strength as he easily crushed his enemies and launched them into walls all with his bare hands.

Interestingly, he has casually torn apart high-level monsters and dismembered them with cold, mechanical efficiency. His strength seems to be in the dragon-level threat range, placing him at least on par with mid-to-high S-Class heroes.
With incredible superhuman-type physical strength, he also has exceptional speed. In combat, Amai Mask moves with blinding quickness, often finishing fights before his opponents even register what happened. For instance, during his battles, his movements were fast enough to appear instantaneous, and he was able to counter multiple opponents simultaneously.
Moreover, he can also dodge attacks simultaneously while launching his own. His reflexes also allow him to strike surgically, targeting vital points with ease. During the Monster Association arc, it’s revealed that Amai Mask is a human-monster hybrid. He was the result of a biological scientific experiment that made him both aesthetically perfect and abnormally powerful.
Also, despite being a polished and perfect hero in the eyes of others. Amai Mask harbors a brutal, near-sociopathic sense of justice. He has no problem killing enemies outright and has stated multiple times that those who fail to meet his moral standards. It would be anyone who gets the tag of worthless in his eyes who could be the target.
On one hand, his unwavering resolve gives him the focus to do what others won't. On the other hand, his rigidity can make him inflexible and prone to emotional instability when things fall outside of his ideals. In this series, he solely wants to protect the purity of heroism and shape public sentiment. In many ways, he is not just a fighter; he is a brand, and that makes him dangerous in both politics and combat.
Comparison with Other S-Class Heroes in One Punch Man
To understand how powerful Amai Mask is in One Punch Man, it would be helpful to compare him with notable S-Class heroes. Against Genos (pre-upgrade), Amai Mask holds the upper hand in both strength and speed. Genos mostly uses technology and weapons. Genos has always been poor in terms of raw physical strength. Amai Mask's regeneration and close-combat capabilities make him a superior fighter in one-on-one situations.
Tatsumaki, on the other hand, is on a completely different level. Her psychic abilities allow her to dominate without physical engagement, and Amai Mask’s combat style would be ineffective against her telekinetic might; he wouldn’t even get close. It is safe to assume that Amai Mask is powerful enough to be stronger than lower-ranking S-Class Heroes, but not so much that he takes the top 3 position.
To sum it up, Amai Mask in One Punch Man is a fairly strong character. His monstrous physical strength, combat skills, regeneration, and psychological tactical skills place him near the mid-to-upper tiers of the S-Class, likely above heroes like Genos and Zombieman.
But One Punch Man is not just about strength because if it were, Saitama would have easily become a S-Class hero. It's about control, identity, and intention. In the current state of the manga and anime, Amai Mask remains one of the strongest non-S-Class heroes, and perhaps one of the most dangerous characters overall.