I think that Men were clearly created to be mortal. It would seem that the Dwarves and Hobbits also ended up that way. However, supposedly the Orcs were Elves that Melkor had corrupted, so does that mean that they also were immortal and could only die the way Elves could? As for Mair and Valar, would they too fade if they stuck around in Middle Earth too long? I know the Elves would, though I'm not sure if that applied to older Elves or if, say, Legolas had chosen to remain and had fathered Legolas II who then fathered Legolas III and so on to Legolas LXV, if the "fading" would only start hurting the ancestor Legolas after a certain amount of time or ages, or if it would quickly start to affect Legolas L - Legolas LXV too. (In short, I could see it affecting those born in the First Age, and eventually the Second and Third Age, but would fading start to happen to Elves born in the Fourth and later ages. As for undead, it would seem that, except for two notable cases (Elrond and his brother) and possibly another (would Aragorn's children, being half Elf, get to decide whether to be Mortal (Men) or Immortal (Elves)?), it would seem that Men were supposed to die. However, supposedly Sauron's dark arts were able to keep the Nazgul around long after the lifespan of even the oldest and most noble of Men of the First Age. How was Sauron able to override the mortality of Men if Eru put in place? How did the Nazgul become "living ghosts"? And, more confusingly, how did the Oathbreakers somehow exist as wraithlike things or whatever they were? How could anyone curse them to supposedly not go on and die but be forced to remain till they could keep their oath? Also, if the Firstborn (Elves) are supposed to be immortal, how can they, save suicide, decide they don't want to be immortal anymore? I know that Luthien (or whatever her name was that married Beren) did this and I think Arwen did this too when she married Aragorn. How does that work?