[Elmo]

Is it Arda, Legate?

For so long time I'm here: It's been around a pretty long time I guess
though not from start of times. It was created the ainur etc
In greatest treachery Is it the corruption in Arda by Melkor which led to the damage in Elvish's hroa and the like
I at first took my part.

I saw how Darkness comes For all this - its the world I suppose it see pretty much every thing
I saw how it departs.
I saw how it returns,
I saw the death of stars,
I saw corrupted hearts.

Once They will come to me - Eru and the ainur
to undo treachery - Melkor's
at that day, it all ends
I'll die by my own hands. I'm not sure about the end myth...