So the third arc turns from a fanfic about anime worlds to a xuanhuan world during the era of pangu and the creation of humans by nuwa etc. If it's just this it wouldn't be so bad but it's as if a different author took over from here and the MCs personality took a 180. The MC suddenly turns into an arrogant, indifferent to lives young master who did everything based on whether it was fun/amusing or not. Pretty the the first thing he does after getting to the new world is killing and framing provoking a major war between all the races which pretty much massacred over 10 million lives just cause. He literally never met any other living being yet or did anyone provoke him nor did he have to do it cause of the system. He literally just arrives in the new world and starts immediately on causing a war. There's no explanation on why he does it either. The author never mention why, its as if the the author just assumed everyone reading will somehow know that according to legends a war will happen anyways so lets make the MC the mastermind behind it.

Another thing is that the MC enjoyed the entire process of manipulating everything and sitting above the clouds while watching millions of being slaughter each other because of his actions. This is so different from how he was just a couple days back when he was in the Naruto world. In naruto it's explained that his system works by collecting belief to form incense which gives him new powers and makes him stronger so he did everything to fight and protect people so they would worship him. But in this world its as if the author went and forgot about it cause its never mentioned again. Instead the MC goes on and on about how he is the true god and everything exists for his amusement which includes being the mastermind behind wars which destroys millions of lives an annihilating several races (which he does more than once too) for no reason. Not because someone provoked him, not because they threatened him and not because he had to for the system to collect something. He did just cause according to his knowledge it'd happen in the future anyway so he'd just make it happen faster and bigger cause it'd be more fun. He stops caring about whether they are good or bad, instead he keeps going on and on about how he is a true god and the lives of others are no longer worthy of his care. An example is that he caused a flood that wiped out dozens to hundred of villages of weak powerless civilians, and he was like they should be glad to be sacrificed for my plan.

Another thing is the timeskips. He spent less than 5 years in one piece and naruto together but in this third world after spending a week or 2 to killing and framing to cause the war to happen, a couple days for the war to end then boom, 34000 years pass. The time skips become so ridiculous, it's like every other chapter several thousand years pass. For a guy who had trouble waiting so much that the system had to forcibly accelerate time 6 years in naruto so events happen sooner to spending 34000 years doing nothing but wait like it was the most natural thing ever. No mention of how he felt or what he did during the time either. It's like the author once again just assumed readers will work it out themselves again and didn't bother writing why or how.

ability to have unlimited devil fruit powers

Apparently there are dinosaurs in East blue somehow. And according to the author, people with bounties in the hundreds of millions just wander East blue. And then it went from belli currency to gold and silver coins...I stopped reading One piece after the time skip, but I don't know if that became a thing.

Also, MC is overly OP. He can get and use all devil fruits. No limitations. Unfortunately, he became s*upid all of a sudden.

He is getting crew members in a similar order to Luffy as well with the navigator and swordsmen. It is lacking a bit of originality.

He even gave away the healing fruit so far to his one and only crew member. So apparently no one can get in the water on that ship. He says its for her protection, but she is a non-combatant, and if she falls in the water from not being able to protect herself, she'll die anyways.