In the Great Pirate World, I Start a Holy Grail War!

Does it mean being killed by a single punch from a magma fist?

Much better than those argumentative brats, and the writing is quite good too. A rare gem, please write more. If we consider it a world where Servants have been enhanced, then logically there shouldn't be any problems.

The protagonist, like a traitor, brings all sorts of trouble and disasters to this world, thinking he can make it a better place. In the end, he does nothing, acts like he knows everything, but everything goes beyond his control. He even calls himself a "funny guy" and thinks he sees the Celestial Dragons as pigs, only to discover that the protagonist is the biggest pig in the world.

After so many years of time travel, nothing from the original plot has changed, and they're still using the original characters as stepping stones—it's really unbearable.

Personally, I feel most readers came because of the Type-Moon tag, and I suspect Chen Ge himself is more focused on Type-Moon-related settings and casting. However, since it's set in a pirate world, there's currently a bit too little content about pirates. Perhaps some more material could be added, perhaps to make up for some of the original shortcomings (though this might backfire on Oda).

Napoleon angrily denounced the navy for killing civilians.

I still hope this kind of story doesn't have a main character, but rather everyone is a main character. Having a main character leads to characters who are arrogant, face-slapping, and stupid, like various anime characters. When a character's favorite is slapped in the face, it becomes repulsive. (The Holy Grail War, Dragon Ball War!) Were well-written, but the early chapters were good, and then the author suddenly stopped writing properly, like an AI novel.

The first Holy Grail War was well-depicted, showing the struggle between various forces and powerful individuals. The subsequent battles between the Heroic Spirits and the natives were also good, without any one side being unfairly treated, and all the necessary levels of intensity were present. However, the first Holy Grail War ended just like that. Okay, so how should we write the rest?

If the power gap is too large, it's not interesting. If there are only Heroic Spirits, it's okay, but the power gap can easily jump around; it depends on the author's control.

The premise is too ambitious. The protagonist is supposed to be the strongest pirate ever, travel through time several decades, and still follow the original storyline, with Roger becoming the Pirate King, the Four Emperors dividing the seas, participating in the God Valley Incident, and not needing either the Blue Dragon Fruit or the Paw-Paw Fruit, simply slaughtering the Celestial Dragons.