[quote=@LadyRunic]
The Elves all leaving for Valinor was a mistype. I was thinking and speaking more of the realm that many of them HAVE left and are leaving.

<Snipped quote>

Morgoth is darkness, lies, deceit. And while you may win a battle or war against him. He will continue. As he is immortal, As he was once joined with the Valar, Blessed by the hand of Eru. He can very well return.
[/quote]

I'd argue that the whole point of him being banished into the void at the end of the first age implies an impossibility of his return. The only thing ever to come out of the void without the will of Eru was Ungoliant, and even she was defeated and cast off.

Anyway, I'm still interested, hope this goes up.