One Piece isn't long because its an endless merry-go-round. Rather, its story is incredibly dynamic and endlessly shifting, expanding the story much more than it recycles it. The main difference here is that characters are susceptible to change, as the journey and actions of the Straw Hats have wide consequences that affect the furthest ends of the sea and the deepest parts of other characters.

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This is most evident in the ever changing tides of its villains who, after having their plots thwarted, may either continue their dastardly deeds or embark on new and life changing journeys. This list will be examining both types, as it runs down some villains who surprisingly became heroes as well as the few who typically stayed bad.

10 Stayed Bad: Rob Lucci

Rob lucci from one piece

Rob Lucci was the main threat during the Ennies Lobby. He held the last of the keys that the Straw Hats needed to free Nico Robin, and he was the mightiest of the CP-9 agents. He came to embody a lot of the elements that came to define the worst of the World Government: unbridled prejudice, overwhelming power, and a total disregard for an enemy's life.

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Though he'd be defeated and would desert the Marines, he'd later return to join its CP-0 division. While in CP-0, he's pretty much been carrying out the same shady deals for the World Government. His job and attitude hasn't really changed, and it seems that he's actually been promoted. Good for his career. Bad for anyone who happens to cross the World Government.

9 Became A Hero: Nico Robin

Nico Robin wearing a hat and looking over her shoulder in One Piece.

Nico Robin was once the trusted second to Sir Crocodile during his operations over Baroque Works. As his partner, she was entrusted to oversee the activities of his various agents, handle certain assassination duties, as well as decipher the hidden poneglyphs within Alabasta.

Despite working for the corrupted Warlord, Nico Robin would actually go on to help Luffy when he was near defeated and actually attempted to fight back against Crocodile when he drew to the poneglyphs. Having switched sides and abandoned the life of a demon child, Nico Robin now uses her talents for the Straw Hats.

8 Stayed Bad: Buggy The Clown

Buggy the Clown ranks as the Straw Hats' oldest, most recurring enemy. Ever since East Blue, he's been chasing Luffy down to exact his revenge. Things would take a turn for the better, when he'd actually help Luffy find his brother in Impel Down. However, he only did this to get the bracelet Luffy picked up from Thriller Bark, a clue to finding Captain John's treasure.

During the Paramount War, he never voluntarily helped Luffy and even used the situation as an opportunity to build on his own infamy. Since then, he's continued lying to maintain his status and continued to greedily amass as much money as he can.

7 Became A Hero: Eneru

Eneru leaning on his side in One Piece

Eneru was once the god of Skypeia who used his advanced mantra abilities and Rumble Rumble Fruit to quickly defeat and usurp its past god. During his reign, he'd tyrannically rule as a wrathful god, quickly smiting those who deny his rule and using slave labor to build his golden ship.

In a surprise turn of events for the Straw Hats, he'd actually successfully carry out his master plan and used that golden ship to fly to the moon. It is there that he became a hero, when he'd fight against space pirates to defend a community of robots. He'd even use his powers to revive the community's dormant, ancient members and become the moon's benevolent ruler.

6 Stayed Bad: Arlong

Arlong of the Sun Pirates

Arlong was the cruel ex-member of the Sun Pirates who was shoved off to the East Blue and started his own campaign to take vengeance on humans. While there, he'd start the Arlong Pirates and invade Nami's village, killing her mother and ruling over the community with a scaly fist. Since Luffy defeated him, he hasn't really reappeared in the series, but he was shown in a touching flashback during the Fishman Island Arc.

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Showing humanity's cruelty towards Fishmen and even its enslavement of them, fans finally understood why Arlong despised humans so. However, it didn't really do much towards changing his character. Arlong was still a huge jerk back then, and he kind of played a pivotal role in defining the prejudicial monster that is Hody Jones. Fans might hate him less, but he hasn't exactly redeemed himself.

5 Became A Hero: Hachi

Hachi Ready To Fight In Arlong Park

A member of the Arlong Pirates who did redeem himself is now happily working on Fishman Island as a takoyaki vendor. Hachi is the octopus fishman who fough Roronoa Zoro in Arlong Park. While he has a colorful personality now, he was a huge player in the subjugation of Nami's village and her overall psychological torture.

Despite this, he'd try to befriend the Straw Hats when they came to the Sabaody Archipelago. While there, he would actually sacrifice himself for Luffy's sake, when Luffy tried to raise a hand against a Celestrial Dragon. Though his efforts were in vain, he has more than garnered the forgiveness of Nami and established himself as a kind friend to the Straw Hats.

4 Stayed Bad: Akainu

Fleet Admiral Sakazuki Speaking To The 5 Elders

Admiral Akainu was the bane of the Paramount War. He was the final Marine admiral to be revealed, and he carried the harshest attitude towards pirates. He'd slaughter various pirates, manipulate one of them into betraying Whitebeard, and would even raise his burning fist against a young Marine just trying to get the senseless violence to stop.

Much like Lucci, Akainu hasn't changed but instead been promoted for his dedication to defending a warped regime. Though he's shown little remorse for his actions during the Paramount War, his stubbornness only makes fans more excited for his eventual battle with Luffy.

3 Became A Hero: Bentham

Bentham really wasn't a villain for very long. As soon as he met the Straw Hats, he'd quickly befriend them. However, duty called, and he would quickly raise his ballerina legs to fend off Sanji to defend Baroque Works. Despite this exchange, he'd have a surprising change of heart and would even distract the Marines during his own arrest to help the Straw Hats escape Alabasta.

He'd continue this good will during Impel Down, when he'd not only help Luffy during his quest to save Ace but also sacrifice himself to help Luffy escape Magellan's wrath. Though he is still imprisoned, Bentham has taken on the kind, supporting role as the new leader of Impel Down's hidden level.

2 Stayed Bad: Blackbeard

Marshall D. Teach — also known as Blackbeard — using the Gura Gura no Mi

It would make sense that the central villain of the series would still be pretty bad long before the series ended. Blackbeard's reign of terror has persisted since Paradise, when he'd tour the seas to destroy kingdoms and accrue infamy. He captured Ace, betrayed the World Government, and would even ambush Whitebeard during the Paramount War.

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During the time skip, he'd go on to hunt down various Devil Fruit users and would even defeat the remaining members of the Whitebeard Pirates. Since then, he's continued his campaign to burn as many bridges as possible by launching attacks against the Revolutionary Army. To make things worse, he's even gotten his hands on the previously lost Gecko Moriah. Suffice to say, he hasn't really been doing the world any favors.

1 Became A Hero: Helmeppo

One of the grandest examples of character progression in the entirety of One Piece, Helmeppo was once the spoiled son of the corrupt Marine officer "Axe Hand" Morgan. He was the one responsible for capturing Zoro at the beginning of the series and forcing him into weeks of starvation.

He would also be responsible for one of the most hilarious instances of One Piece's localization, when he'd infamously hold a pistol/hammer gun to Koby's head. While funny in the localization, it was a threatening gesture nonetheless. Things change, however, as a long friendship with Koby and a harsh training period under Garp turned that sniveling brat into a brave, Marine willing to protect and cry over the same boy that he once held at gun point.

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