Seinnen One Piece:
*Art style could be a little less cartoonish,don't know how i would go about that.
*Random pirates battles would actually involve murder,looting,rapping and kidnapping of women.
*Luffy would have a collection of scars from all his major battles.I would just make him smarter and mature.Less luck/destiny shit and more Luffy pulling off genius stuff to get out of extreme situations.His morals are right.Killing your enemys is not the way.Crushing their dreams is the way.
*More death of named characters.
*More gore like in berserk.
*Male/Female nudity.
*Romance/Sex every fucking arc(sanji gags lol).
*Boa sisters would have suffered from sex slavery too(for drama).
*Kuja warriors would have their secret of only producing only female babys revealed:abandoning male babys in Rusukaina.Luffy would find out about this by stumbling upon a mass graveyard of baby skeleton and we would get a flashback of Luffy fighting Boa and changing the culture of the Kuja to accept man and boys.All shortly before Sabaody 2.0(leaving for the new world).
*Nico Robin backstory would involve prostitution in order to survive.
*Nami would have suffered more physical abuse(violence) due to Arlong's racist nature.
*Dressrosa and Wano would be way darker:Orochi and Caesar could be pedophiles.Kaido would be more like Genghis Khan:more brutal executions and sadism.Doffy and Viola relationship would involve sex,abuse and mental illness(stockholm syndrome).
*Dragon would have a more radical ideology and would endorse the assassination of celestial dragons and Kings.Nobody would be shocked by Sabo.
Katakuri would have actually developed a grudge vs BM after Luffy's fight.Luffy would make him realize her narcissism and abusive tatics to keep her kids under a leash.
Big Mom would actually be sexy,smart,competent and narcissit.Making her way more scary.I would keep her beautiful despite her old age and actually use her sex appeal to seduce Kaido into an Alliance(in theory she call steal souls to keep her youth).
*I would set up Shanks as a traitor to Luffy,basically using him to become PK.
*Straw hat ships:LuffyxNami,ZoroxRobin,Sanji would bang ladys and leave kids behind in each island.
*Cipher Phol would be brutal criminals doing all sorts of shady things for the WG.
*Mihawk wouldn't train Zoro and would actually send him away to learn haki by himself.Mihawk would actually lose the respect he had for Zoro.
*Admirals would have poor backgrounds and have suffered losses of loved ones in the hands of pirates.Thus making their will strong to grow up and become pirates slayers.
*Bounty Hunters would play a important role.We would see some chopped heads of pirates defeated by straw hats being handed over to marines for booty.Mihawk would not be a pirate,but a bounty hunter like Zoro.WG would still send SSG after him out of fear for his might.
*Law and Kidd would not be Luffy's cheerlanders.Law would be grateful to Luffy for defeating DD,but he would still see him as a rival.I think Oda is actually doing this.But Law should have a colder attitude towards the straw hats.
*Rocks D. Xebec would be a fucking animal/vermin and all mighty(stronger than Roger).
*Okama people would be as they are.
*Ussop would piss and shit himself at some point.
*A few straw hats deaths would happen in Wano.But we would get new crew mates.
*The topic of failed dreams/heros would be brought often to challenge Luffy determination.Not everyone suceeds in life.
*BB is good as he is.But i would make him even more violent and nasty looking.
*Pell and some other death fake out victims would actually die.
*Robin would offer herself to Crocodile to achieve her goals.No romance.Just raw sex.
*Nami would be more slutty and be a gold digger.
*Brook would use his skeleton body to scare people as a gag.
*Chopper would be an angry doctor.
*Franky would have a more serious and stoic attitude.
*Jinbe would harbor real hatred towards the celestial dragons,but would not be racist towards humans overall.
*Boa x Luffy would be a story of platonic love.Luffy will never love her and that would make her more melancholic after post-time skip.
*Ussop would have been humiliated a lot pre-skip.Post-Skip Ussop would come back as a brave warrior of the sea already.I would give him COC,very strong coo and coa coating.He would be a competent fighter and a heroic figure post-skip.He would be a legit "God Ussop".
*Crocodile and Moriah would be cases of strong pirates losing their haki due to depression and mentall illness.
*Yamato:drop the "i'm Oden act" and make her more of a tomboy.She kinda is already.
*Vegapunk would be a lunatic "Angel of Death Mengele" type of scientist.
*Kuina would have commited suicide(fell of the stairs means this in Japan).
*Less backstories for side characters and more adventure/exploration and philosophical presentation.
*Less stupid gags for badass characters like Vergo.That food thing was not funny,just lame.
I think seinnein One Piece would actually be worse.It would resemle game of thrones too much.I like the light hearted nature of the world Oda created.
