Luthien and The Sun Blackens

[Ivriniel]

When Beren, with Thingol's people hunts Carchorotth, after his and Luthien's return from Angband, purposes to recover the Silmaril, Luthien, "sickens" of the sun going "black". She does not venture with Beren, because of it.

We are also warned, through Melian's grief, when she learns of Luthien's choice of Mortality, and in relation to that grief, that being "...greatest..."--it seems--due to her separation from Luthien, at Death.

Is this to the Purpose of the Last Battle and the Second Prophesy of Mandos? Where we know Valinor is a bastion of Arda unmarred. Is this also the place where the Valar and Eldar are preparing for that event?

I was also placing Manwe's grief at the Darkening of Valinor, who, and in relation to Feanor, we are made aware, that (Feanor), had he not, in his madness, taken the Oath, was expected to have wrought, yet "thrice" more than the Silmarils. Which is also a second warning from the non-allegorical emphasis--in relation to hatred, vengeance--and especially Pride. To the Marring of Arda