Heroes have a lot of admirable qualities. They're brave, strong, and protect the innocent, but despite being some of the most popular characters in all of anime, a lot of them are also complete screw-ups. Sometimes they mess up so badly, they throw away a victory and allow their enemies to gain the advantage.
Some heroes are naive, arrogant, or just plain dumb. They try to save the day, but they can let these characteristics get in the way of success. These heroes, for all of their virtues, were tripped up by their faults and seized defeat from the jaws of victory.
10 Vegeta Lets Cell Power Up
Dragon Ball Z
Dragon Ball fans have been clamoring for Vegeta to get that long-awaited win over a major villain for years. He might have gotten it a couple of times if his arrogance and drive for a good fight didn't get in the way. Vegeta has Cell completely outclassed but allows the bio-android to absorb Android 18 and achieve his perfect form.
Vegeta is so confident in his own abilities that he endangers the Earth just to get a good fight. Instead, he gets a one-sided beat down. Sadly, Vegeta's not the only Saiyan with this problem. Even with Dragon Balls, it's a miracle Earth has survived this long.
9 Ash Blows An Insurmountable Lead In The Unova League
Pokémon
Until relatively recently in his twenty-odd years Pokémon career, ten-year-old Ash Ketchum has been a perennial loser. Perhaps Ash's worst defeat came in the Quarter Finals of the Unova League against his friend Cameron.
Cameron's one of the few trainers less intelligent than Ash and only brings five Pokémon to a six-on-six battle. Yet despite this advantage and having three Pokémon left compared to Cameron's last option, Riolu, Ash blows the lead with his last three Pokémon being swiftly defeated.
8 Yugi Lets Joey Win
Yu-Gi-Oh!
Strapped to an anchor in a duel against his mind-controlled friend where the loser is dragged to the bottom of the ocean, it's understandable that Yugi wouldn't go all out. He cares about Joey in Yu-Gi-Oh! and spends most of the duel trying to free him from Marik's control.
Despite going easy on Joey, Yugi still manages to gain the advantage; he is the King of Games, after all. With the chance to blast Joey and win the duel, Yugi instead turns his final trap card on himself, resulting in his defeat and potential drowning. Luckily, a now-freed Joey jumps in after him, saving his life.
7 Eren Doesn't Pay Attention To His Surroundings
Attack On Titan
When Reiner and Bertholdt reveal themselves as the Armored and Colossal Titans in Attack on Titan, Eren finally gets the chance to take revenge on the people who destroyed his home. He goes toe-to-toe in a brutal mixed martial arts match with Reiner.
Thanks to his training with Annie, Eren's able to gain the advantage, pinning down Reiner. But his iron-clad focus on Reiner distracts from the simultaneous battle between the scouts and Bertholdt above them. Without realizing it, Eren's been forced directly under the battle, allowing Bertholdt to drop in and knock him out. Eren eventually gets his vengeance in a rematch with Reiner.
6 Korra Loses Control Over The Avatar State
The Legend Of Korra
Korra is not at her best when she first fights with Kuvira in The Legend of Korra. While the removal of the metallic poison gets rid of the physical trauma she received from her fight with Zaheer, her psychological trauma remains.
After taking a bit of a beating, Korra finally uses the Avatar State to gain the upper hand on the conquering tyrant. However, just as she's about to finish off Kuvira, her psychological trauma reemerged. She snaps out of the Avatar State from shock and lost the duel in the process.
5 Boruto Gets Disqualified
Boruto
Boruto makes it to the finals of the Chunin Exams, where he and Sarada face off against Gaara's adopted son Shinki. Shinki is an incredibly powerful opponent, and Boruto is barely able to defeat him using Kakashi's signature purple lightning.
The problem is, Boruto was cheating the entire time by using an illegal scientific ninja tool. Considering he's surrounded by the most powerful ninja in the world, he's caught and disqualified. This cancels out his victory and sees him temporarily stripped of his rank as a ninja. It's one of Boruto's worst moments.
4 Goku Powers Down Too Soon
Dragon Ball Super
Like his rival Vegeta, Goku has a tendency to throw away an easy win or let the bad guy escape. Perhaps his most egregious mistake came during Frieza's resurrection in Dragon Ball Super, where he had the advantage over the Galactic Tyrant. Frieza hadn't yet fully mastered his Golden Form, leaving him unable to keep up with Super Saiyan Blue.
Goku could easily have finished Frieza off but instead powered down, offering Frieza the chance to escape, come back, and fight again. In doing so, Goku left himself vulnerable to a laser shot from Frieza's henchman Sorbet, leaving him completely incapacitated.
3 Ace Is Goaded Into His Death
One Piece
One Piece's Battle of Marineford is fought between the Navy and the White Beard Pirates over the execution of Portgas D. Ace. The battle has countless casualties on both sides, but the White Beard Pirates appear to achieve their objective and rescue Ace.
As they're fleeing the battle, Admiral Akainu taunts Ace to face him, and Ace is quickly outmatched by superior fire (or lava) power. More importantly, this draws Luffy into the line of fire, allowing Akainu to launch a fatal strike toward Ace's younger brother. Ace jumps in front of the attack, dying in the process, resulting in the War being a total failure for the pirates.
2 Mirio Loses His Quirk Protecting Eri
My Hero Academia
Mirio is able to take full advantage of his Permeation Quirk, demonstrating a level of skill that puts him among the top Pro Heroes despite only being a student. Mirio puts that skill on full display against Overhaul, the leader of the Shie Hassaikai.
Mirio is quickly able to gain the upper hand, as Overhaul can't even touch him. However, Mirio's heroic nature drives him to shield Eri from a Quirk-erasing bullet, costing him his powers. It's an act that proves he's a true hero, but it's also one that costs him a fight he was probably going to win.
1 Vegeta Lets Frieza Blow Up The Planet
Dragon Ball Super
Vegeta messes up so often that it's no surprise he's managed to let his excessive pride flub an easy victory. This particular screw-up is made worse when it comes only a couple of minutes after Goku failed to kill Frieza when he had the chance.
Vegeta takes too long to destroy his long-time tormentor, wasting time throwing in a few final taunts. This gives Frieza the opportunity to blow up the planet, killing Vegeta in the process. Luckily, the two Saiyans were bailed out by a deus ex machina thanks to the angel Whis reversing time to undo the damage.