Navy's Dark Admiral

He was a Marine Admiral, praised by the world as the light that pierced through the haze, Holy Gun Longinus.
He was the king of the Underground, feared by the world as the darkness that ended the era, the Evil Sword Apophis.
Wandering in the light and darkness, he weaved the war song of blood and fire.
When he suddenly looked back, he found that the world had been trampled under his feet.
PS1: This book has no fruit and no system, the title of the book has nothing to do with the Dark-Dark Fruit!
PS2: The timeline is very long, starting from the day Roger started the Great Age of Pirates!