My Hero Academia's Toshinori Yagi, better known as All Might, is the former no.1 Hero and Symbol of Peace. He drained every bit of his One For All Quirk to defeat the villain All For One, but his golden days as the world's top superhero will never be forgotten.
All Might could be considered the anime equivalent of Captain America, but how would he fare against Marvel's token bad guys? Comic book villains come in all forms — from laughably dull to ridiculously overpowered — and, at his prime, the MHA legend could've easily defeated most of them. However, every hero has their limits and some of Marvel's most infamous criminals are far beyond Toshinori's pay grade.
10 Can Defeat: Red Skull
Johann Schmidt, aka Red Skull, is one of Captain America's greatest foes, meaning he's a match made in archenemy heaven for All Might. If Steve Trevor can hold his own against the Nazi general, the Symbol of Peace could certainly emerge victorious in a hypothetical matchup, especially in terms of brute force.
It's worth noting that Schmidt's powers blossomed as the result of a Super Soldier formula developed by Abraham Erskine, the same man that "created" Captain America, so to speak. This means that the two share several traits — enhanced strength, speed, and intelligence, for example — but it's nothing that a well-timed Detroit Smash can't handle.
9 Can't Defeat: Dark Phoenix
Since the Phoenix Force is immortal, killing Jean Grey is a fool's errand. No matter how much damage is done to its physical vessel, the Force itself cannot be destroyed.
All Might would be out of his depth against such an otherworldly being. Grey's telepathy alone would be enough to overwhelm the former no.1 Hero. In All Might's defense, nearly every Marvel character in existence would also be decimated by Grey in a legitimate confrontation.
8 Can Defeat: Doctor Octopus
Otto Octavius's greatest advantage lies in his intelligence. He's a brilliant scientist with proficiency in various fields, but this probably wouldn't help him in a scuffle with All Might. As a matter of fact, Toshinori's intellect is noteworthy in its own right.
The key to besting Doctor Octopus is to overpower him before his gadgets have a chance to do some damage. For instance, he once used a Golden Octobot to swap bodies with Peter Parker. Being the quick thinker that All Might is, he could skillfully prevent such a scenario from occurring in the first place.
7 Can't Defeat: Loki
Thanks to Tom Hiddleston's charming portrayal in the Marvel Cinematic Universe, it's easy to forget that Loki is incredibly overpowered and brazenly deceitful. As an Asgardian, Loki developed sorcery skills that could contend with the likes of Doctor Strange. This spells danger for the likes of All Might, who heavily relies on his physical abilities to defeat villains.
Loki has been known to shape-shift, manipulate minds, conceal his presence, and generate illusions. Very few heroes could keep up with such a chaotic catalog of powers and Toshinori would definitely end up in a sticky situation if he tried.
6 Can Defeat: Green Goblin
Proving to be quite the problematic father/son duo, both Norman and Harry Osborn have used the Goblin Formula to induce superhuman capabilities. Green Goblin benefits from enhanced reflexes, impressive strength, and a suitable regenerative healing factor.
While Green Goblin profits from many physical boosts, All Might's inherited Quirk surpasses those stats by an alarming degree. It would take a lot more than a few explosives and a Goblin Glider to overthrow Nana Shimura's successor.
5 Can't Defeat: Thanos
You don't need to be a comic book fan to comprehend the threat that Thanos poses as a super-villain. The Titanian Eternal garnered pop-culture fame thanks to his prominent role in the MCU, albeit lacking the charisma that makes Loki so appealing.
Thanos can manipulate matter and energy while also flaunting a terrifying amount of brute strength. The majority of his skills are beyond comprehension, even without the Infinity Stones, meaning that All Might doesn't stand a chance. There simply isn't a "Smash" strong enough to negate such versatile power.
4 Can Defeat: Kingpin
Wilson Fisk has no superhuman abilities and that already places him at a massive disadvantage against someone like All Might. However, there's a reason that heroes like Daredevil and Spider-Man have struggled with Kingpin's presence time and time again.
Kingpin's impeccable hand-to-hand combat skills complement his hulking size. On top of that, he has countless criminals at his beck and call at all hours of the day. While posing a very credible threat, Kingpin wouldn't be able to hold up against a barrage of All Might's attacks. Toshinori always puts villains in their place with a smile on his face and Fisk's intimidation tactics would never be able to deflate his indomitable spirit.
3 Can't Defeat: Ultron
The most accurate way to describe Ultron would be a sentient, overpowered robot and, truth be told, Toshinori wouldn't fare too well against him. The MCU didn't fully expand on his list of abilities and he poses a far greater threat in the comics than what was presented on the big screen.
Strength, speed, and durability aside, Ultron has a vast array of weapons at his disposal. This is the same character that created a throng of flesh-eating drones, so there's no doubt that he would be able to bring All Might to his knees.
2 Can Defeat: Juggernaut
As his name implies, Juggernaut is quite a force to be reckoned with and his power levels are far too absurd to ignore. Cain Marko is, for all intents and purposes, virtually immortal thanks to the gifts provided by the Crimson Gem of Cyttorak. He serves as an intimidating response to the Hulk, a hero that he once defeated in Marvel's comics.
That said, Juggernaut has been stopped time and time again by heroes less powerful than All Might. Even someone like Hitoshi Shinso could humble the "unstoppable" villain since he's susceptible to psychic and mental attacks. It would be a cinematic power struggle indeed, but All Might would emerge victorious in the long run.
1 Can't Defeat: Super-Adaptoid
Super-Adaptoid is basically Marvel's very own All For One and My Hero Academia already provided the outcome of a confrontation such as this. The menacing copycat has yet to appear in the MCU, so fans who haven't read the comics might not be familiar with its abilities.
Super-Adaptoid profits from power mimicry and can copy up to eight beings at once. Toshinori depleted every ounce of One For All against a villain with these same talents and ended up retiring as a result. It's safe to say that the conclusion of a hypothetical battle against Super-Adaptoid wouldn't be any different.