I love that in Ep 26, Vash abandoning his coat at the end was meant to symbolize him finally letting go of Rem. Nightow’s original suggestion for the ending was that Rem would appear and Vash would lead her by the hand before she faded away.
The director considered the idea, but later changed it into Vash abandoning his coat and moving forward as we’ve seen, while keeping the same emotional and symbolic core.
Nightow said he asked himself, “What would Vash need the most after everything?” The answer he arrived at was that, after everything he went through, Vash would need to shake himself free from Rem—an idea reflected also in Vash’s own words when he says he will continue to believe in her, but from now on he will search for his own words.
I just love this ending a lot because of all the things it implies. Vash still believes in Rem, but he’s no longer only following her shadow. He chooses to search for his own words, his own ideals, and walk his own path. That shift shows that he is beginning to carry her memory differently—not through grief, sorrow, and guilt as he once did, but as a gentle memory he can always remember with a real smile.
In a sense, he frees himself from the past after confronting Knives, but he also frees Rem.
Source: Roman Album TRIGUN ART BOOK/Yasuhiro Nightow interview