I think it’s interesting that Oda ends the chapter on a panel of Garp. The last couple pages are interspersed with memories from various characters from over the course of Ace’s life. Garp is naturally the only person left from when he was born, and it’s a common storytelling technique to juxtapose life and death. He was the one who was present for both events.
I also think it really hammers home the tragedy of what could have been. Ace was born with the name Gol but died as a Portgas, as emphasized by the volume and chapter titles. Rouge herself dies in an act of loving sacrifice, and Ace is killed because of the burning hatred of the world. Garp saw and was in a position to shape the person Ace would grow into but chose to stick with the marines, leading a boy to grow up with a burden of self-loathing that would contribute in part to his death. He saw it all, could have helped, and instead did nothing. Garp loved Ace and weeps for his grandson while allowing himself to be held down—metaphorically shackled—by the same military power that had hunted him since before he was born.
I’ve had people argue that Garp doesn’t truly care for his family because of his choice to stay by the marines, and I think this is categorically untrue. But there are times where a feelings of love and affection aren’t enough to overcome harmful actions.
Ace is dead, and while Garp isn’t the one who killed him, he certainly did nothing to save him either.
