[saberience]

I'm not sure I like that you say this as though it's an absolute truth versus your own interpretation of what "elves" are and this theory about them turning into woodland spirits.

First of all, elves appear in many different books, series, movies, and there are no hard and fast "rules" for elves. I mean, they're fictional first of all! There are no dogmatic universal laws governing them.

Also, in the Lord of the Rings, there is nothing canonical that states elves lose their bodies and become woodland spirits without "magic."

[Amezarak]

Elves do Fade and become disembodied spirits haunting remote places, maybe even to this day, according to Tolkien. Manipulating those spirits was the main reason Sauron was called the Necromancer.

It’s just a natural process that has nothing to do with “sources of magic”, Elves lived the vast majority of their time in ME without “sources of magic.” This conceit came from Rings of Power, I am pretty sure.