Would the Half-Elven vanish if they wore an elven ring?

[Puddleglum]

Originally Posted by Galadriel55

My only disagreement with you here, Puddleglum, is that though Luthien chose to be mortal, in my eyes she never became a (wo)Man. Half-Elven can chose between Elves and Men because they have the blood of both. Luthien is a Half Elf... Half Maia. So in my opinion she was allowed to leave the circles of the world with Beren, but she could never be one of the Edain.

I wonder if this is only a semantic difference (my apologies if I am misunderstanding your meaning, it's not intentional). Silmarillion seems clear that she become mortal "Then she would become mortal, and subject to a second death". Whether than means she became specifically Edain (or did you mean to say Atani?) or not seems less important to the question of whether her fate as being part of the larger classification of "mortal" (having the gift of Illuvatar vis-a-vis departing Ea forever) had implications for her child, Dior.

The general rule that seemed to be followed was that, if both parents were Mortal (had the gift to depart), then their children would have that gift as well. If one or both parents did NOT have that gift, the matter was uncertain (at least until Manwe made his ruling).

Elwing's brothers are, indeed (I think) a case we are never told about. Maybe, since they came to Valinor via death (ie, straight to Mandos), Mandos treated them as having the gift and they departed without the matter coming to Manwe.

In Elwing's case, she had broken the Ban of the Valar by coming, in the flesh, to the Blessed realm (with Earendil). That sort of forced the issue and Manwe had to make a decision both formal and public.