Can the Valar Sentence People to Death?

[Galin]

As an aside: I would say Morgoth was killed; he incarnated himself and had become wedded to his body it seems, and was ultimately judged and executed.

This is arguably more explicit in Morgoth's Ring (and/or possibly Osanwe Centa) than in the Silmarillion. What the MR text might also say about Manwe or Eru here I don't remember however, and I don't have Myths Transformed at hand at the moment!

Edit: here's the 'arguably more explicit' passage I was thinking of (found it on the net), but I know there's more in any case...

'Morgoth was thus actually made captive in physical form, and in that form taken as a mere criminal to Aman and delivered to Namo Mandos as judge - and executioner. He was judged, and eventually taken out of the Blessed Realm and executed: that is killed like one of the Incarnates.'

Full context is best but again I can't lay my hands on MR at this time.