Summary
In a world of superheroes and super villains like the one inMy Hero Academia, it’s inevitablethat climactic battles are reoccurring eventsthat not only give audiences a thrilling diversion, but also have an enormous impact on each character’s development.
There have been many times whenlosing a fight has changed a character forever,regardless of whether they’re a hero or a villain. However, characters that died or disappeared were not taken into account here, only those who had a lot of development as a result of a hard-hitting defeat. These are some of the best examples of this occurrence throughout the course ofMy Hero Academia.

8All Might
Lost To All For One
Toshinori Yagi, better known asAll Might, is the #1 Pro Hero of Japan and the famous Symbol of Peace. Reaching such a prestigious status was not easy, as he was forced to go through many trials and tribulations before he could call himself that,and the most important event in All Might’s lifewas undoubtedly his initial encounter with the villainous All For One.
Despite fighting alongside his powerful mentors,Nana ShimuraandGran Torino, their combined strength was not enough to defeat All For One. Nana even sacrificed herself so All Might could live on and get stronger. After this tragic defeat, Toshinori traveled to the United States and became a powerful hero so he could later go back to Japan and ultimately get revenge on his nemesis.

7All For One
Lost To All Might
Things were not easy for the villain, either, sinceAll For One– one of the main antagonists ofMy Hero Academia– also had to go through some harsh defeats in order to become stronger. Firstly, he was brutally defeated by All Might when the hero returned to Japan, who completely destroyed the Symbol of Evil’s head and forced him to retreat and lie low for many years.
Even after All For One managed to come back, and even arranged the initial lineup of the League of Villains, he fought All Might and was defeated once again. Because of this, he had to change his strategy completely, and began relying on his successor,Tomura Shigaraki, way more.

6Ochaco Uraraka
Lost To Katsuki Bakugo
Since the beginning of the series,Ochaco Urarakahas always been seen as a sweet girlwith a useful Gravity quirkperfect for assisting, but it was not so fitting for actual one-on-one fighting. So, when she was pitted against Katsuki Bakugo during the U.A. Sports Festival, everybody was surprised, as they all thought this was an unfair match-up.
Uraraka did not hold back, and showed him how strong she truly was, to the point that she even came up with her own Ultimate Move. Even though Bakugo respected her enough to treat her like any other opponent, she was ultimately defeated. This didn’t matter, because Uraraka could now show the world that she could be an efficient fighter, something that would later inspire her to intern in Gunhead’s agency and become proficient atGunhead Martial Arts.

5Katsuki Bakugo
Lost To The League Of Villains
Katsuki Bakugowas not always a pleasant person to be around. Despite his impressive talents and incredible strength, he acted extremely arrogant, stubborn, and rude, even against those who wanted the best for him. This hubris is what let the League of Villains kidnap him during the Forest Training Arc.
Even though his classmates offered to escort him back to camp so he could be safe, Bakugo rejected their offer, which gaveMr. Compressan opening to swiftly kidnap him and take him back to their hideout. This triggered a chain of events that led to All Might’s rematch against All For One, which forced the #1 Pro Hero to retire. Bakugo felt extremely guilty of this and began blaming himself for All Might’s retirement, something that wouldchange his outlook on heroism (and his relationship with Deku) forever.

4Izuku Midoriya
The rivalry betweenIzuku Midoriyaand Katsuki Bakugo goes way back. Since he was born quirkless, Deku has always felt inferior to his longtime rival. This changed when he inherited One For All, which let him become a Pro Hero and attend U.A. High School. Despite this newfound strength, he still couldn’t defeat Bakugo. They clashed many times, but their most significant battle was after the Provisional License Exam.
Since he felt guilty about All Might’s retirement, and he failed to get his Hero License, Bakugo forced Deku to fight him in what ended up being an incredible battle that showed off both characters' abilities. Despite all his growth and power, Deku still couldn’t defeat Bakugo. However, this somehow ended up being a win for both of them. He confessed that he was All Might’s successor,and began working together with Bakugo so they could both get even stronger, making Deku realize that he could really trust his old friend.

3Kai Chisaki (Overhaul)
Lost To Izuku Midoriya And Tomura Shigaraki
Under the villain name ofOverhaul,Kai Chisakibecame one of the most malicious entities in the world ofMy Hero Academia. He was the leader of theShie HassaikaiYakuza organization,and he used both his quirk and his power to exploit a vulnerable little girlso he could erase quirks from the entire world.
Fortunately, the heroes manage to raid Overhaul’s base of operations, rescueEri,and imprison him after Izuku Midoriya gave him an incredible beating. His misfortunes did not end there, as Tomura Shigaraki confronted him after he was arrested and cut both of his arms off, which prevented Chisaki from ever using his quirk again. After all of that, Overhaul turned into a shell of his former self, as he became obsessed with waking his boss from his coma. He even listened to Deku and agreed to someday make amends with Eri, which was a shocking development.

2Rikiya Yotsubashi (Re-Destro)
Lost To Tomura Shigaraki
Re-Destro(Real nameRikiya Yotsubashi)used to be one of the biggest villains in this world, since he’s the descendant of the legendary villain Destro and the President of the Detnerat Company, which let him found the modern Meta Liberation Army. However, Re-Destro ended up making one enormous mistake: messing with Tomura Shigaraki and the League of Villains.
Re-Destro really thought that he could defeat Shigaraki, and he was actually really close to doing so, but he accidentally triggered Shigaraki’s memories, which resulted in the awakening of his Decay quirk. Because of this, Re-Destro suffered an incredible defeatand agreed to join forces in order to establish theParanormal Liberation Front, where he became Shigaraki’s compliant underling. This is quite sad for someone who used to be such a feared villain.

1Enji & Shoto Todoroki
Lost To Dabi
During the Paranomal Liberation War, the fiery villain known asDabirevealed that he was actuallyToya Todoroki, the long-lost son ofEndeavor(The #1 Pro Hero at the time) and the brother ofShoto Todoroki. The shock of this unexpected twist left Endeavor speechless, which prevented him from fighting back when Dabi targeted him with his flames.
Luckily, Shoto Todoroki confronted him, and both siblings used the sameFlashfire Fistattack. However, despite his undeniable power,Shoto’s flames were no match for Dabi, who ultimately knocked him out and later escaped alongside the rest of the League of Villains. This fateful encounter almost ruined Endeavor’s recent character development and growth, but his family helped him realize that they could all fight together in order to defeat Dabi and bring Toya back. This defeat gave both Endeavor and Shoto newfound purpose and motivation to team up against a shared opponent.
