Sils and Morgoth

[Carannillion]

I don't recall ever reading that the Valar cannot be destroyed. Could you point me in the right direction, Elrian?
I do recall, however, that actually destroying Melkor would have been catastrophic (apocalyptic?) because his essence was present and bound up in nearly every created thing.

Can you destroy another person? Can you destroy anything? Killing is one thing, but destroying is another.

Ilúvatar did say something about how all things are boud to the Music, and the things of Arda shall dwell there until the end of Arda. Then, Ilúvatar shall unmake Arda, and all his children (creations, stuff etc.) shall join him for a new purpouse or something, which only Ilúvatar himself knows.