Characters who will not return to One Piece

The narrative structure of One piece ensures that many characters are placed in scenarios where they can return to the story, even after a long absence. That said, even with the opportunities afforded by this structure, there are a handful of characters we likely won't see again, due to various circumstances. The exact reasons behind each character vary, and most of them are united only by the fact that the narrative seems to have, for better or worse, left them behind with no easy way to return. These characters have probably already made their last, if not one of the last appearances in the series.

7 Nero

Probably dead

Nero was a member of Cipher Pol 9 (CP9) who only knew four of the six Rokushiki techniques, having not learned Tekkai and Shigan. Despite being slightly inferior to most of his colleagues, he was able to hold Franky for quite some time. However, his relative inexperience led to him being expelled after repeated failures. He was injured by Rob Lucci and thrown into the ocean during a storm known as Aqua Laguna.

There is still no official confirmation that Nero was killed, leaving open the slim possibility that he could have, somehow, survived the storm. Yet even if that were the case, it still wouldn't result in further apparitions. This is because Nero is basically too unimportant a character to be declared permanently dead. Perhaps he could reunite again at the end of the series, along with other characters who aren't killed off, but given his immoral nature, probable death, and relative unimportance, there's little to properly reinsert him into the series.

6 Lord Jones

Aged quickly

Hody Jones is one of the first serious villains in the Post-Timeskip era One piece. He is the captain of the new Fish-Man Pirates and a blind believer in Arlong's ideals, knowing nothing of the humans he claims to hate so deeply. He attempts to conquer Fishman Island by force, which he would use as a springboard to enact an unclear plan to take over the world. Yet for all his talk, he and his crew proved incapable of facing even the highest-ranking soldiers of Fishman Island without some form of support.

To this end, they continuously consumed energy steroids, which would temporarily increase their physical strength. Although this led to premature aging, it gave them additional strength. However, these steroids not only did not prevent their defeat, but also ultimately aged them beyond the point where they could fight. Hody in particular ate the most steroids and appeared to suffer even more than his peers. They were all imprisoned for their crimes.

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Considering the fact of their rapid aging and the story's lesser focus on the Fishman supremacist groups, there seems little reason for Hody and his crew to properly return.

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3 Enel

The man on the moon

For all the significant plot revealed throughout the Skypiea arc, it cannot be ignored that it takes place on completely different terrain than the established blue seas seen throughout the majority of the story. This fact can be seen through characters who have little interest in what happens next, one of which is Enel. This self-proclaimed “God” seems largely satisfied with his takeover, frustrated only by his inability to discover the Fairy Vearth, a legend told by the Birkan people.

After his defeat against Luffy and, more importantly, his loss of power in Skypiea, he instead focused his efforts on finding the Fairy Vearth. As it turns out, this was, in fact, the moon. Enel eventually encountered automatons on the Moon, there to avenge their creator, who died in an explosion caused by aliens on the Moon. Shocked he said that the aliens were desecrating the Fairy Vearth, he knocked them out himself. After using his electrical powers to revive the defeated automatons, he discovers an army of them underground, as well as evidence linking the races living in the sky, and decides to rule the moon.

When you consider his apparent satisfaction with this goal and the apparent lack of people negatively affected by it, it seems unlikely that Enel will return, unless his moon base comes into play somehow.

2 Jozu

In hiding

Jozu was a prominent member of the Whitebeard Pirates, being one of its 16 division commanders (most notably leading the 3rd Division). His Devil Fruit allowed him to transform his body into a nearly indestructible diamond, at the expense of mobility. If positioned correctly, it could prevent even a powerful blow from Dracule Mihawk, the world's strongest swordsman, from causing damage.

However, the death of his captain, Whitebeard, and his teammate, Ace, during the Summit War seemed to spell the end for the Whitebeard Pirates. This was expanded during the War of Revenge, where the remnants of the crew lost to the Blackbeard Pirates. They have since gone into hiding and the whereabouts of most members are currently unclear.

It's not impossible that Jozu could return, especially if what happened to the other surviving crew members became something to focus on, but there seems to be little opening for that at the moment. For the moment it can be assumed that he is hiding, although it is not clear where exactly.

1 Gaimon

Guarding the island of rare animals

Gaimon is a man who fell into a treasure chest, and presumably he is One piece author, Eiichiro Oda's favorite character. This fact, along with the hair that had since grown out, had given him a strange but endearing appearance. He fascinated Luffy to the point that the captain asked him to join the Straw Hat Pirates. Gaimon refuses, having grown fond of the island's rare animals and feeling an obligation to protect them.

She has since developed a relationship with the future emperor, Buggy, when he was briefly on the island. A seemingly more permanent resident is Sarfunkel, a woman stuck in a barrel similar to her own situation. The two seem romantically involved, due to her affectionately nurturing him. The two were two of many seen listening to Vegapunk's message, but this may be their last appearance. Factors limiting Gaimon's involvement aside from his desire to remain on the island include its limited relevance and low combat capability.