[Galin]

If the myth as it was found in HME V was to survive in any way, I think Christopher Tolkien concluded, in any case, that it was not to be thought of as coming from Mandos.

'Here ends The Valaquenta. If it has passed from the high and the beautiful to sadness and ruin, that was of old the fate of Arda Marred; and if any change shall come and the Marring be amended, Manwë and Varda may know; but they have not revealed it, and it is not declared in the dooms of Mandos.' JRRT

The Second Prophecy of Mandos (V. 333) had now therefore definitively disappeared. This passage was used to form a conclusion to the published Silmarillion (p. 255).' CJRT

It is to be noted that JRR Tolkien never did a substantial rewrite of the end of the Quenta Silmarillion of the 1930s, specifically the passage in question. Later Tolkien did make cursory corrections to the (now) 'old version', however. Christopher warns that these revisions need not imply 'any sort of final approval of the content' (see his reasons in HME XI, The Later Quenta Silmarillion). In any case, these revisions include:

'Turin Turambar... coming from the halls of Mandos' (changed to) 'Turin Turambar... returning from the Doom of Men at the ending of the world'. (as noted by Mr. Hicklin already). In the margin JRRT wrote 'and Beren Camlost' without direction for its insertion. 'and she will break them [The Silmarils] and with their fire rekindle the Two Trees' emended to 'and he [Feanor] will break them and with their fire will rekindle the Two Trees.'

Aprroximately against the last two sentences of the paragraph (from 'In that light the Gods will grow young again...') Tolkien put a large X in the margin of the manuscript. There is also the introduction of a further subheading The Second Prophecy of Mandos.

Hmmm, did Tolkien abandon the Second Prophecy or not? With respect to Turin dealing Morgoth his death blow we find (in HME XII) a prophecy concerning Turin from Andreth the Wise-woman rather -- and here Turin will return at the 'Last Battle' at the end of the Elder Days and before he leaves the Circles of the World forever will deal Ancalagon his death-stroke (noting that it had earlier been Earendil, as was taken up into the constructed Silmarillion of course).

This idea dates from 1968 or later: Turin is no longer named 'among the gods' (1930), no longer given a place among the 'sons of the Valar' (1937) and is seemingly coming back to slay Ancalagon rather than Morgoth (according to prophecy anyway), and during the War of Wrath. Author's Note 7 to Athrabeth Finrod Ah Andreth (in Morgoth's Ring) is interesting:

'It is noteworthy that the Elves had no myths or legends dealing with the end of the world. The myth that appears at the end of the Silmarillion is of Númenórean origin*; it is clearly made by Men, though Men acquainted with Elvish tradition.' JRRT

*note 19 '... in so far as this reference is to any actual written text, this is the conclusion of QS (V. 333,... ) the Prophecy of Mandos.' CJRT

The Athrabeth itself probably dates to the late 1950s so this note is quite important in my opinion. Again, to note the Valaquenta here: 'if any change will come and the Marring be amended ... it is not declared in the dooms of Mandos' -- and the new prophecy of the 1960s regarding Turin indeed does not come from Mandos in any event, but from a mortal woman.

Only a part of a complicated subject in any case!