Though My Hero Academia's Midoriya Izuku is one of the hottest names in Shonen anime as of recent memory, it's no secret that he's far from the top of the totem pole when it comes to Shonen power. To be fair though, Deku has gotten significantly stronger within recent years. Far from the crying mess that All Might found, modern Deku has fused Batman's quiet, skilled intensity with half the powers of any X-Men class.
He's no slouch as an anime hero, and while there are entire worlds between him and the likes of Saitama and Son Goku, there are still plenty of interesting characters to compare him to, especially with the Shonen landscape constantly shifting.
Rock Lee (Naruto)
It's tempting to compare Midoriya Izuku to Naruto Uzumaki, especially considering that My Hero Academia's creator, Kohei Horikoshi, has ittedly taken inspiration from Konoha's #1 Hyperactive, Knucklehead Ninja. However, that would be a huge disservice to the real dream battle between the franchises.
While Naruto has arguably always been overpowered with the gifts of the Nine-Tailed Fox, the same can't be said for Rock Lee who struggled his way from being powerless to arguably being more powerful than even Naruto. In the battle of the underdogs, Rock Lee, however, comes out as a decisive winner given how his speed and strength factors have scaled to outrageous degrees compared to Deku's.
Asta (Black Clover)
Much like Deku, Asta was just a fragile (albeit, not quite as timid) boy who had the opportunity of a lifetime when he was gifted powers. It's also interesting to note the small window between Black Clover's and My Hero Academia's releases. These two were the prime progeny of Shonen Jump's new generation and were both entrusted for paving the way for future series.
And, while Deku has become much more of a household name, there's no denying that Asta has outpaced his colleague in the whole "overpowered anime character" department. Asta's fighting and magical abilities have grown through exponentially terrifying feats while Deku has stayed relatively grounded as a character.
Akira Fudo (Devilman Franchise)
When thinking of the 1970's Devilman series, there's a lot to compare between Deku and Akira Fudo. Both are timid yet aspirational heroes who use powers thrust upon them by fate to fight crime. Both even have a litany of strange and incredible powers that do a good job of separating them from their Western, superhero counterparts.
However, even looking at the mild-mannered, 1970's version of Akira and Masaaki Yuasa's profoundly sadder and gorier rendition in the Netflix Original anime, Akira is the stronger and more versatile combatant, having plenty of examples to bring fear to both demons and fans alike.
Giorno Giovanna (JoJo's Bizarre Adventure)
Giorno Giovanna is easily one of the most inventive and versatile protagonists to arrive in the anime scene as of late. To rival Deku's own diverse move set and cunning, Giorno's base abilities allow him to grant life to virtually anything, allowing him to both heal his allies as well as create seemingly infinite openings on a battlefield.
Still, when looking at their base kits, there's an argument to be made for either fighter, especially considering Deku's incredible strength. However, what truly seals the deal for GioGio is his requiem Stand which gets both a significant strength boost as well as the ability to send an opponent to an even more hellish version of Groundhog Day.
Mob (Mob Psycho 100)
In a perfect world, Deku and Shigeo would be friends and classmates, constantly cheering the other on in the trials-and-tribulations of school and each gushing about their respective mentors. However, because anime fans can't have nice things, it is the natural thing to put these two marshmallows in a fire and see who can escape the blaze first.
While Mob does come from the same mind that created a guy who can finish off an opponent with one punch, he's nowhere near as invulnerable as Saitama and has shown some of his limitations in battle. However, while Deku would need only a couple of punches to deal with Mob, Mob's psychic abilities would likely overwhelm him before then as evident by some of Mob Psycho 100's best episodes.
Tsuna (Katekyo Hitman REBORN!)
Midoriya Izuku has no better parallel within Shonen manga and anime than Tsunayoshi Sawada. In so many words, these two are the crybaby protagonists of the Shonen world, the ultimate underdogs in an industry where that word gets thrown around godlike aliens. Tsuna himself was a below-average kid who struggled in both his academic and social life.
That is until a magical, baby hitman told him he was the heir to a mafia empire and, alongside some time-travel fun, gifted him confidence, fire abilities, a tiny lion sidekick, and some friends. With Tsuna and Deku competing at full strength, Tsuna's wide variety of tools and powers could show Deku what a real, crime boss is like.
Meliodas (The Seven Deadly Sins)
Deku and Meliodas are both deceptively adorable and likable characters within their respective franchises. Meliodas in particular is the friendly barkeep who knows everyone's name and always tries to keep spirits up. Just looking at his size is enough to disarm even the most hardened of warriors.
However, as is the theme of a lot of anime, one should never underestimate even the smallest of fighters. Competing against Deku's line of powers from One for All, Meliodas is incredibly strong and quick and wields the ability to deflect attacks with exponentially increasing value. And that's not even touching Meliodas' hidden, dark side.
Koro-sensei (Assassination Classroom)
Deku has had quite a few, powerful teachers throughout his time at U.A. but likely none have been quite as dangerous and skilled as Assassination Classroom's own unkillable teacher. Capable of moving at Mach 20 speeds, blasting through walls with resounding force, camouflaging himself, and escaping with a variety of countermeasures, Koro-sensei could be one of Deku's most powerful foes yet.
That's not even touching the fact that Koro-sensei was one of the world's most ruthless assassins whose fighting ability and experience could easily rival Deku on a level playing field.
Rimuru Tempest (The Time I Got Reincarnated As A Slime)
While Deku isn't exactly the most intimidating high schooler, he at least has some stature over slimes, one of the RPG genre's most underrated species. Rimuru Tempest however changes the game entirely. As part of one of the funniest and most popular isekai anime around, Rimuru is one of the most deceptively cute anime characters around. Starting out as a blue blob reminiscent of a famous Dragon Quest design, Rimuru utilized an odd proclivity for eating to gain power after power.
Though isekai characters are not always known for their power, Rimuru has definitely eaten through a few pantheons to become one of anime's most overpowered characters. Rimuru could easily defeat Deku and even take his precious One for All, too. If some of Rimuru's powers don't make sense to you, that may be because you haven't read the Tensei Slime light novels.
Krillin (Dragon Ball)
Krillin has a pretty bad reputation around the anime community for being one of his series' weakest and most defeated characters. However, given that his series is Dragon Ball, one should take that evaluation with a grain of salt. Compared to the rest of his series' Earthlings, Krillin is one of the strongest people in Dragon Ball, managing to fight back against intergalactic threats with powerful strength, his iconic Destructo Disc, and some good, ol' martial arts.
Even though Deku stands as his series' protagonist, fighting against the forces of evil with superstrength, black whips, and the power of friendship, even he doesn't stand a chance against those at the bottom of Dragon Ball's pecking order.