Yeah, a group of world-ruling founding families killed and tortured an immensely powerful man-god so that they might restructure the world to their whim. The people also live in a world divided into 4 sections, with some areas between that. That happened in One Piece.
One Piece is not narratively structured in a genuinely hopeless manner though, and it is only the physical rather than the greater metaphysical world that seems messed up, due to the actions of utterly corrupt humans, allegorically mirroring our real world.
Idk if you mean the soul cycle? That only leads to negative outcomes if a large group of people are erased from existence. I guess becoming too strong while having a job in the Gotei 13 does kinda mean you could end up being condemned to Hell after death for the protection of the innocent, but I don't think anyone knew that, and the elite Shinigami in Hell do seem to be having a good time, so I think they're as strong in Hell as they were outside of Hell.
I mainly mean the unrestrained might makes right system where innocent souls are systematically preyed upon to absolute degrees and live in dystopian tyrannical settings, with no greater good or genuine justice within the metaphysical order.
This just literally isn't true, and the idea lends itself to a eugenicist viewpoint.
I am a spiritual humanist pro-human and animal rights democratic socialist, not remotely a eugenicist, but according to my extensive personal experiences and available information, including from a 25 to 30 years researcher in this area that I know personally, it requires absolutely enormous amounts of works for "sociopaths" (people with antisocial personality disorder) to develop even tiny degrees of conscience and empathy, and with only small success rates for even that, whereas it is completely hopeless for psychopaths and extreme narcissists.
You seem to think of the roughly 81% or so of humanity who are not inherently leaning towards either good or evil, and can go either way depending on their environments and available information and impressions. They are redeemable, yes. The inherently evil part of humanity are almost always not, and again, tricking good or neutral people into believing that psychopaths are just misunderstood and had a bad childhood, will only turn them into much easier victims.
Because the narrative itself isn't the same as the personal decisions of individual characters.
He was, however, in prison, before he was let out by Urahara, who was attempting to channel his abilities to something more positive. However, before Urahara could do that, he was exiled, and the higer-ups kinda just gave him free rein, and people can't really kill him legally, especially because killing a captain and messing around with the Reiatsu cycle kinda messes things up, and if there's an invasion, not having a captain-class fighter on hand would be entirely negative.
Furthermore, if I recall, by the end of the series, most of his experiments on other sapient entities are on the dead, and out of eyesight, and he does do pretty much every "villainous action" for what he sees as the greater good of everyone. A mercy killing kind of deal.
Well, my impression is that the designated protagonists act as voices of the author's personal values in this case, and letting somebody morally equivalent to the most satanically evil real world Nazis run rampant with absolutely atrocious human experiments simply due to tribalist allegiances does not remotely sit right with my sense of morality.
And again, this is fiction. Imagine Dragon Ball if they'd just let Krillin kill Vegeta.
Vegeta is an absolutely power-mad narcissist who has casually committed genocide on innocent planetary populations. Some crimes are too severe to ever be forgiven no matter what, so making him one of the designated "good guys" doesn't remotely sit well with me either.
Fiction, among other things, represents memetic information, ideological values, and personal self-perception/identification narratives. It has massive real world consequences on the people who consume it to sufficient degrees, just like all other media propaganda.
None of them are nihilistic, life inherently does have a provable physical meaning in their universe.
Well, it is certainly extremely focused on might makes right amoral tyrannical systems of social Darwinism, absolutely ruthless tribalism, and obsessions with death, including making all of it arbitrary and hopeless. Which is a form of moral nihilism.
Since the One Piece analogies have been pretty consistent, imagine it as the God Valley incident. Who's in the wrong there, Garp and Roger or Rocks? Technically, Garp and Roger protected the Celestial Dragons. However, they also protected the innocent slaves and former denizens of that island. Now imagine that instead of a single island, everyone in multiple dimensions was being threatened, and rather than preserving the reign of a group of slaveholders, they were protecting every society on all worlds.
Upholding and defending a genocidal supremacist system of tyranny and slavery is evil no matter how you justify it, so although you can rationalise Garp as being internally morally broken in this specific area, due to the overwhelming nature of fighting against said system, and instead attempting to do what little good he can to protect regular people from pirates, while shutting his eyes for all the evidence regarding that he is still acting as an enforcer and bodyguard for a satanic system, the people in the moral right who truly saved innocent people from being massacred for sport were mainly Kuma, Ivankov, and Ginny.
I can agree to disagree, but I see many flaws with this interpretation.
And I see many flaws with yours. So again...