There is, as
Melkor posted, later references to these
Balrogs being slain by these
Elves . . .
. . . and yet . . .
. . . why, in a
very late text about
Glorfindel (Glorfindel II), did
Tolkien do this:
" . . . a chieftain of Gondolin, who in the pass of Cristhorn ("Eagle-cleft") fought with a Balrog Demon, whom he slew at the cost of his own life."
Why cross out the word
Balrog and replace it with "Demon"?
The text continues, including another reference to a
Demon:
" . . . from the wreck of Gondolin a Demon out of Thangorodrim, and so enabling Tuor and Idril . . ." And in the margin, Tolkien wrote
Demon again:
"The duel of Glorfindel and the Demon may need revision."
And yes, a Balrog is a Demon -- but not the only kind!
By this point, we have Orc-formed
Maiar for example, referred to several times in earlier texts (see
Myths Transformed,
Morgoth's Ring). And written at the same time as the "Glorfindel texts" (see Last Writings, The
Peoples of
Middle-Earth), Tolkien mused about the
Dwarves -- long story short, referring to
Durin's Bane as a
Balrog.
So again, why make the change to Demon in the Glorfindel account? Could it be that Tolkien --
who after all had written (at least at one point) that there should not be supposed more than
three Balrogs, or at most
seven, ever existed -- could it be that Tolkien was thinking about having Glorfindel sacrifice himself to a great (possible
the greatest) Maiarian Orc-captain instead?
By Eru!
And what if the number was three? Well, we could still have
Ecthelion, Glorfindel, and
Gandalf slaying their respective rogs . . .
But Elthir, you wasp nest poking trouble maker, Glorfindel had been
famous for slaying a
Balrog, for
decades and decades, do you
really think Tolkien would change this?
Well, we all know Tolkien rarely changed his mind
Anyway, looking again at the
early Fall of Gondolin, where more than fifty Balrogs were slain, Glorfindel does not stand out here as a Balrog-slayer --
at least in the sense that he alone killed many Balrogs, for example (at least as far as I recall in the text) -- but as a much beloved
Elf who gave his life fighting a Balrog. . .
. . . and it became a famous fight nonetheless, and still do the Eldar say when
"they see good fighting at great odds of power against a fury of evil: "Alas! 'Tis Glorfindel and the Balrog Demon."
Okay okay, the word
Balrog remained in the early text . . . but why did this particular fight become so famous?
First, I'd say it wasn't just a valiant fight by
any Elf, but
"Glorfindel was most dearly beloved" and
"Because of their love, despite the haste and their fear of the advent of new foes, Tuor let raise a great stone-cairn over Glorfindel ( . . . ) but the folk of the Golden Flower wept at its building and might not dry their tears."
If you are so well loved already, you get remembered.
Also, Tolkien actually notes -- in the tale itself -- that this fight was seen:
"Now there was a deadly combat upon that high rock above the folk; and these, pressed behind and hindered ahead were grown so close that well nigh all could see, yet was it over ere Glorfindel's Men could leap to his side."
Well nigh all could see. And more love for our golden-haired paragon. . .
"Now the folk that had passed into the Eagle's Cleft and who saw the fall of Glorfindel had been nigh eight hundreds -- a large wayfaring, yet was it a sad remnant of a fair and numerous city. But they who arose from the grasses of the Land of Willows in years after and fared away to sea, when spring set celandine in the meads and they had held sad festival in memorial of Glorfindel, these numbered but three hundreds and a score of men and man-children."
Glorfindel gets a memorial! Again, much beloved, his battle seen by many . . . I think he'd still be famous and beloved if it had been a huge Maiarian
Orc captain. Indeed a Demon!
.
.
.
Or not.
For myself, I think Glorfindel killed a
Balrog 