Do nobodies run on "borrowed time"?

[Gram]

Its something I've always wondered by came back to mind as I played through 2.5 (KH2FM). Several times it's mentioned that the nobody eventually fades back into darkness.

An empty vessel whose heart has been stolen away... A spirit that goes
on even as its body fades from existence

Namine also remarks once that she thought "nobodies were doomed to fade back into darkness".

I know we had Ansem the Wise's apprentices existing as nobodies for a decade plus but no limit is given to this fading away. (could even argue the stronger the nobody the longer it takes to disappear)

But it makes me wonder. If they truly do eventually just go poof essentially then does that mean the body they were born from dies?
They're born of a persons body+soul and a soul going out is what the Secret Ansem Reports refer as "death" in the series. (though what happens to the heart after isn't bluntly made known)

EDIT: Also what if the nobody forms a new heart for itself?

 

[Absent]

Perhaps it all ties in with the idea that a Heart is the most necessary/important component for life, without it they're slowly fading away like a starving body. Or maybe Yen Sid and Ansem think they know everything about Nobodies.

 

[Blackdrazon]

My impression of the second line was that it was Yen Sid diminishing the potential of Nobodies. "Nobodies are good for nothing except to fade back into darkness because they serve no purpose in the operation of the world." More his talking about the operations of Fate/Doom then the physical functions of a Nobody.

As for the first line, the one in the quote box, I think it's just a mess. I think it's saying that the Nobody is created as the original body fades away: it's a byproduct. The problem is derived from confusion between the terms "body" and the lack of a term to apply to the Nobody's physical form.

"An empty vessel whose heart has been stolen away" - The entire Nobody.
"A spirit that goes on" - Still the entire Nobody.
"even as its body" - the flesh-body.
"fades from existence"

So yeah, I think what he's trying to say is the body - the grisly bits - fade away, leaving behind a Nobody, made out of whatever Nobodies are made out of (cloth?). It's a byproduct the same way the Heartless is a byproduct of the heart... while also sort of being the Heart?

Nobodies are bodies and byproducts of bodies, Heartless are hearts and byproducts of hearts.... This series needs to take better care of its dichotomies.