One Piece has a myriad of powerful characters that are blessed with incredible powers. Currently, there are many pirates who are actively pursuing the title of "King of the Pirates."
However, there are many characters who have hung up their boots and no longer seek action. These One Piece characters have become inactive for various reasons, but most of them have stopped fighting because of their age or because they have had their fill of action.
8 Silvers Rayleigh
Silvers Rayleigh was the right-hand man of Gol D. Roger. The entire crew achieved the impossible by traveling around the Grand Line and finally reaching Laugh Tale. After the crew's exploits, Roger disbanded the crew, and all the members went their separate ways, Rayleigh being one of them.
Rayleigh reaffirmed in the Sabaody Archipelago that he was no longer active and that he was not keen on fighting. But when the lives of the Straw Hat Pirates were threatened by Kizaru, the Dark King stepped in and even made the Admiral bleed. From the fight, it is evident that Rayleigh is still among the best fighters in the series, and his reputation alone is enough to scare most opponents.
7 Jaguar D. Saul
Jaguar D. Saul is a giant who used to work for the Marines. He was a Vice Admiral, with a solid reputation. Saul is a giant with immense strength, and he can easily destroy multiple ships with little to no effort. Saul also possesses both Busoshoku and Kenbunshoku Haki. Saul abandoned his position after he learned about the World Government's plans to exterminate every single person in Ohara.
Saul accidentally ended up in Ohara and was frozen by Aokiji during their confrontation. He was presumed dead by everyone, but it was later confirmed that he had survived. Currently, Saul is in Elbaf, and he is no longer interested in fighting.
6 Scopper Gaban
Scopper Gaban was one of the strongest members of the Roger Pirates. He was confident that he could fight against Kozuki Oden, who was an absolute monster. Unfortunately, Gaban has not been involved in the story as much as Rayleigh.
There is no information available about Gaban's current whereabouts, but it is plausible to assume that he is still alive. Like Rayleigh, Gaban seems to have retired, so it is highly unlikely to see him in action again.
5 Shiki
Shiki was originally a member of the Rocks Pirates, but he left after the God Valley incident. He started his own crew, which came to be known as the Golden Lion Pirates. Shiki possesses the Fuwa Fuwa no Mi, a Paramecia-type Devil Fruit that allows him to levitate himself and other non-living things.
In his prime, Shiki led a pirate armada and managed to prove himself as a great rival to Gol D. Roger. Shiki is known for invading Marineford and destroying almost half of it in the process on his own. After being captured, Shiki was sent to Impel Down, but the facility couldn't hold the great pirate for long. Shiki has been away from the action for a long time, but he could return when the Rocks Pirates are brought up again in the future.
4 Jozu
Jozu was the Third Division Commander of the Whitebeard Pirates. He was a muscular man and one of Whitebeard's most trusted aides. Jozu ate the Kira Kira no Mi, which allowed him to cover his body with diamonds. The power of the Devil Fruit allowed Jozu to deflect Mihawk's powerful strike with ease.
Jozu was last seen in the Summit War, where he effortlessly knocked away Crocodile and then briefly clashed with Aokiji. Considering the fact that the Whitebeard Pirates suffered two crushing defeats in a row, it's no surprise that most of them have not been involved in any kind of battle.
3 Marco
Marco made a surprise appearance in the Wano Country arc, and he played a massive role in the victory of the alliance. Marco had originally retired after losing the Payback War to the Blackbeard Pirates, but he joined the Wano alliance at Nekomamushi's behest.
Marco is undoubtedly a powerful character. He has fought Kizaru, Big Mom, King, and Queen and emerged pretty much unharmed. After the conclusion of the Wano Country arc, he left for Phoenix Island again, and it seems that he is going to settle for good.
2 Enel
Enel was the main antagonist of the Skypiea arc. He came to the island after destroying his homeland. Enel was a ruthless individual with a severe case of megalomania. He believed that there was no one who could match his strength, but that changed when he met Luffy.
Enel used his Goro Goro no Mi in various ways. He combined it with his Kenbunshoku Haki, which enabled him to keep an eye on all events taking place on Skypiea. Enel's attacks were powered by millions of volts, and they were powerful enough to kill an individual within seconds. After being defeated by Luffy, Enel went to the moon, where he saved the Automata and became their leader.
1 Sengoku
Before the time skip, Sengoku served as the Fleet Admiral of the Marines. He was one of the most respected figures within the organization. When Sengoku was at the zenith of his powers, he was able to fight against Shiki. Sengoku's strength was further praised by Roger, who considered him one of the few Marines capable of challenging him.
Sengoku possesses the Hito Hito no Mi, Model: Daibutsu, which allows him to turn into a giant golden Buddha. In his transformed state, Sengoku could easily damage several members of the Blackbeard Pirates. Following the events of the Summit War, Sengoku stepped down from his position.