Hi, Glenn and Carl!
I feel certain that "Así mi vida es una fuga" should be translated "So my life is a fugue state," given that the narrator has been describing symptoms of a dissociative fugue throughout the whole passage.
See
https://my.clevelandclinic.org/healt...ociative-fugue
Borges builds up to a conclusion in which he is losing his grip on his bodily identity, in addition to his already-lost grip on his famous persona identity. So I also think it's unhelpful in the last line to amend "which of the two" to "which of the two of us." That possessive, first-person "of us" completely undermines the intended distance and lack of connection/belonging that Borges has been describing.
"magnificar" might be translated as "aggrandize":
https://www.wordreference.com/es/en/...pen=magnificar
"terna" refers to a very short shortlist, indeed:
https://www.wordreference.com/es/en/...asp?spen=terna