

He also does not “become a samurai”
Correct. That’s why I said symbolically.
but you never see the character on screen again
I maybe incorrect but towards the end of the movie, the Emperor asks how Katsumoto died, to which Tom Cruise replies “I’ll tell you how he lived”. So he was alive?
tl;dr for others
A: “I have an Pink Unicorn inside the trunk of my car. It vanishes the moment you try to open the trunk or look at it.”
B: “What? That’s absurd”
A: “I know it exists. It’s up to you to disprove it”
B: “But there is no way one can capture/observe/understand it with any sort of scientific instrument”
A: “Don’t care. Skill issue”