What is the black goo? "Darkness" of the devil, or "ink" on the paper?

When I watched the film the first few times, I initially interpreted that famous "everybody in Alex's world exploding into goo" scene on a very deep level. I felt it revealed that his whole world was an allusion that he(or else the Devil himself) had created. Sort of this own little hell for Alex. He was secluded, lonely, and abandoned. Nobody(except for Noah) was real, in fact he was separated from everybody who is real(for example he can't be with Sam even though he goes to her apartment, meets on the same bridge, etc), making his world an allusion. The 'black goo' then represents the Devil's creation, ie, 'darkness'. A darkness/goo which seemed to be alluded to earlier by Noah when he spoke of Alex running from the darkness in his life. Thus the black goo he found in the back of the semi trucks, the black goo in the sky, the goo on the car, and eventually the black goo that everybody explodes into is a representation of that 'darkness' spewed by the devil that Alex life/world is stuck in/getting free from.

BUT!

Watching it again though, I'm beginning to think more about the typewriter, Alex's life as a written script, the pages themselves written in typewriter ink that Sam changes with the 'ink' of her pen. Which makes me wonder if the black goo is not "the devil's darkness" as much as it represents the "ink on the page of his life's script". All these people in Alex's world are characters, literally written into the story of his life. From the lady crossing the street with her child, to the cartel, Bama, pawn shop guy, etc, virtually everybody was created by the 'ink' of the 'divine typewriter'. So when Sam burns the script, pretty much destroying the story, is that big 'goo explosion' simply the characters who originally came alive from the ink on the page, turning back into the ink that they were originally written in?

Is the black goo the devil's darkness, or ink written by the typwriter?..............