The villain redemption story is a popular one in anime, and many of these redemption arcs lead to the villain joining the heroes. Many times, switching sides helps the former villain grow and becomes stronger as they attempt to keep up with the heroes that helped and accepted them.
However, other times, it can be the opposite, with the villain becoming weaker when they join the heroes. This can be because they now have to live by a code of conduct, have to find a new source of power, or they just simply cannot keep up with the heroes and their new rivals and villains.
10 In Avatar: The Last Airbender, Zuko Lost His Bending When He First Joined Team Avatar
When Zuko finally decided to switch sides and help Team Avatar, acting as Aang's firebending teacher, he was dismayed to learn that his firebending was not working. It turned out that, for the majority of the series, his firepower was fueled by rage and hurt, and when he got onto the right path, that fuel was no longer sufficient.
He and Aang were forced to search for a new source of firebending, as without that power, he was weak and basically unable to the fight against his evil father, the Fire Lord.
9 Gaara Had To Focus On Keeping Shukaku In Check And Saving The Village In Naruto
Gaara's power waned after meeting Naruto Uzumaki, but it was for the better. A lot of his power came from the unchecked potential of the Shukaku demon that resided within him. However, when he realized how precious human life and relationships were, he could no longer rely on the demonic frenzy to win fights.
As the Kazekage, he had to protect the whole village, even if the price for doing so was his own life. This was seen best in his fight with Deidara, who tried to blow up the village, forcing Gaara to protect it and leave himself open. Later, he loses the Shukaku altogether. He was still powerful, but less so.
8 Speedwagon Was A Razor-Hat-Wielding Criminal But Became Useless In JoJo's Bizarre Adventure: Phantom Blood
Robert E. O. Speedwagon was a common criminal living in London before meeting Jonathan Joestar. When they met, he attacked Jonathan with his razor hat, but it did not do much to stop Jonathan. Speedwagon decided to follow Jonathan on his quest to destroy DIO.
Unfortunately, Speedwagon was not the same after that, and his razor hat made little appearance in the show. He also did not engage in much fighting. His primary role was as a businessman who funded the Joestar's efforts against the vampires and Pillar Men.
7 Okuyasu's Stand Was Much More Formidable When He Fought With His Brother In Diamond Is Unbreakable
Okuyasu gave Josuke and Koichi a run for their money when they first met. He and his brother, Keicho, proved to be difficult foes. However, Okuyasu saw the error of his brother's ways and decided to help Josuke. When he joined the other side, however, his Stand failed to pack the same punch. Plus, he is not as likely to come up with brilliant plans like the Joestars.
As with many villains-turned-heroes, a lot can be chalked up to the fact that they have to keep up with the power creep. He could not keep up with Red Hot Chilli Pepper and other, newer villains of the show.
6 Hector Tried To Help Humans But Ended Up Becoming A Powerless Prisoner In Castlevania
Hector was a forgemaster who pledged himself to Dracula, and together they did great and terrible things to humanity. However, Hector felt bad about this and tried to plot a way out. At each turn, his plots were thwarted and buried him deeper into the problem.
He became a prisoner of Lenore and Carmilla. He watched humans and vampires die left and right. Most of all, he had to deal with the grief and guilt over betraying his allies and doing more harm than good in the process.
5 In My Hero Academia, Endeavor Has A Hard Time Keeping Up With Nomu After Deciding To Be Less Of A Villain To His Family
Endeavor was a Pro Hero, and after All Might retired, he took the Number One Hero spot. He was not a villain in the eyes of the public, but if one were to ask his family, they would say he was quite villainous. He finally got what he wanted when he became the Number One Hero, so he decided to pay more attention to his family life.
When he began his journey of atonement, however, he also began to slip as a hero. He was barely able to keep up with the Nomu he fought alongside Hawks.
4 Orochimaru Had To Tone Down His Experiments After Joining The Hidden Leaf In Boruto
Orochimaru was a slippery villain who somehow managed to worm his way out of every situation, no matter how bad it seemed. He dodged being imprisoned or killed following the war, and he was ignored by the Hidden Leaf Village while he committed his many crimes. By the time of Boruto, he had changed a lot.
Now, he keeps his experimentation in check, and, for the most part, he is taking it slow. As a parent, he seems to think of the world in a different way and does not pose as big of a threat. He is not a hero, but he helps the heroes, and he seems to be a relatively good parent so far.
3 Piccolo Can't Keep Up With Goku In Dragon Ball Z
In the Dragon Ball series, Piccolo was a formidable foe that caused a lot of strife for the protagonists. As time went on, however, Piccolo changed. In Dragon Ball Z, he helped Goku and Gohan. Eventually, he became a full-fledged hero of the series, as well. However, his power could not keep up with that of the Saiyans'.
The Saiyans are famous for their ability to constantly grow stronger. Their power limits are not as tangible as other beings. Piccolo, though fearsome as a villain, did not shine as much as a hero.
2 Dragon Ball's Yamcha Was A Bandit, But With The Heroes, He Couldn't Win
Yamcha is notorious for being one of the Dragon Ball franchise's unluckiest and weakest protagonists. He started out as a bandit, pitted against the series hero, Goku, but he ended up joining Goku. Yamcha's presence continues throughout the series, but after joining Goku and the gang, he just does not seem to make himself as relevant.
For a human, Yamcha is powerful, but he cannot keep up with the Saiyans, and he also finds himself in predicaments where he is in over his head constantly.
1 Digimon Adventure 02's Ken Ichijouji Is Not As Strong When He Has To Think About How His Actions Affect Living Beings
Ken Ichijouji committed some terrible acts as the Digimon Emperor. However, thanks to the Digidestined, he was able to see just how bad he had been and made a change. After joining the side of good, however, he did not pose as much of a threat to other villains as he had to the heroes before turning good.
Part of this was because he had to take into account every person and Digimon's life, preventing him from being as reckless and thoughtless as he was when he was a villain.