One Piece has a ton of characters, which makes it very interesting, and it allows fans an opportunity to find a personal favorite. Being a series about pirates, one can expect to see morally corrupt characters every now and then. However, some of them are not scared to take things to the extreme.
One Piece characters who fall into this group are far more ruthless and wicked than the rest. They are thoroughly evil, and they only care about their own selves. So, no matter what Oda does, such characters can never be redeemed, and they will always be remembered as the bad guys.
8 Donquixote Doflamingo
Donquixote Doflamingo is unquestionably one of the best villains in the series. His introduction during the Punk Hazard arc will remain iconic forever. He was a truly evil character, who didn't hesitate to pass judgment on his friends and enemies alike.
When he was still a kid, Doflamingo killed his father, and as an adult, he would go on to kill his younger brother. Doflamingo's atrocities didn't stop there as he took over the country of Dressrosa. He turned the nation against Riku and claimed himself to be the savior of the nation. Everything that he did was to satiate his own needs.
7 Kaido
As a young boy, Kaido lived in the Vodka Kingdom, a place that relied on pillaging other places in order to stay on good terms with the World Government. At the age of 10 was considered their strongest soldier and was sold to the Marines in exchange for a spot at the Levely. Being hounded for such a long time made Kaido realize that there was great inequality in the world, and he decided that only in war can people truly be equal.
After years of running away, Kaido eventually started his own pirate crew. While Kaido respected strong opponents, he had no reluctance about killing them. Kaido terrorized the entire nation of Wano and turned most of it into a wasteland. The people of Wano will forever remember the sins of Kaido and his crew.
6 Kurozumi Orochi
Kurozumi Orochi was the ruler of Wano. He had cleverly planned his rise to the position of Shogun. Orochi pretended to be a friend of Oden, while he was secretly taking steps to ensure that Oden would never become the Shogun.
Orochi's devil fruit could be considered a great example of Oda's clever writing. Like a snake, Orochi hid in the dark, lurking for the opportunity to get rid of Oden. Orochi had absolutely no redeeming qualities. He was an evil man, who would punish anyone who dared to question his authority, and luckily for the people of Wano, he met his end on Onigashima.
5 Blackbeard
Currently, a member of the Yonko, Blackbeard has been away from the main story for quite some time. Before the time-skip, Blackbeard's actions led to a war in which numerous people lost their lives. Blackbeard captured Ace, freed notorious prisoners in Impel Down, and stole Whitebeard's devil fruit.
He was also responsible for the death of Thatch, who he killed in cold blood because he wanted to steal the Yami Yami no Mi. Blackbeard is clearly an evil character, who only wants to achieve his goals, making him a very unlikable character.
4 The World Government
The World Government is made up of twenty nations that allied together to destroy the Great Kingdom. At the top of the World Government is Im, and he is looked after by his underlings, the Five Elders. In order to stop their dark secrets from being exposed, they placed an embargo on the reading of the Poneglyphs.
When the scholars at Ohara disobeyed them, the Five Elders gave the order to slaughter all of them. There have been other instances, where the World Government has covered up its tracks by blaming others. The people who are aware of the World Government's actions quite rightly despise them.
3 Kurozumi Kanjuro
When Kanjuro was first introduced in the series, no one expected him to be a devotee to the cause of Kurozumi Orochi, after all, he had been a member of the Nine Scabbards for a very long time. He was even ready to be boiled alive if that meant he would be able to help the clan.
Kurozumi Kanjuro traveled with Kin'emon and co. all the while pretending to hate Orochi. Kanjuro did his utmost to sabotage the plans of the alliance, and they would have never figured it out if he had not admitted to being the traitor himself.
2 Akainu
Akainu is the Fleet Admiral of the Marines, which means that he has authority over every single Marine in the world. He is a firm believer in "Absolutely Justice," and he wants to eradicate every criminal. While his goals sound noble, Akainu is nothing short of a criminal.
When there was a buster call on Ohara, Akainu needlessly destroyed a ship carrying all the innocent people. Akainu claimed that they could not risk any scholar sneaking aboard the ship. At Marineford, Akainu attacked his fellow Marines, which goes to show that he is not the saint that he claims to be.
1 Enel
Not many anime characters have the same level of narcissism as Enel. Originally a resident of Birka, Enel destroyed his entire homeland along with some help from his priests. He then moved to Skypiea where he overthrew Gan Fall and started ruling as the "God of Skypiea."
Enel terrorized Skypiea for a long time and would have continued to do so if the Straw Hats hadn't interfered. Enel was a megalomaniac and a murderer, and he's not deserving of any kind of redemption.