Sator 2/inverted Sator/~ Sator returns to the yacht in Vietnam for his final moments. Why is he not wearing a mask?
1 Answer
Because he is inverted forward there again. Same as Kat.
In Tenet, inverted characters have to breathe their own oxygen while traveling to the past. When, in the past, they find a turnstile and invert forward again, they can breathe normal oxygen again.