Since we are talking about Melkor in his prime here, he takes this HANDS DOWN! He doesn't need a physical form and is literally immortal. He has infinite stamina and infact fought relentlessly with the Valar for 14.373 years and was able to overpower them all at once and only when Tulkas joined the fight was he not able to keep up. He can destroy continents, dry up seas, create entire mountain ranges (the Misty Mountains, one of the largest mountain ranges in Middle-Earth, which is literally 900 miles long, was created during the Years of the Trees by Melkor when he had long fallen from his prime), volcanoes etc.
A weaken Melkor's scream, literally shook the entire earth and tore rocks asunder! Literally Melkor could destroy the whole planet if the Valar and Eru did not intervene, and this is dimished Melkor we are talking about!
"Melkor could do nothing with Arda, which was not from his own mind and was interwoven with the work and thoughts of others: even left alone he could only have gone raging on till all was levelled again into a formless chaos."
Melkor not in his prime literally did this:
"Also some of the Wise have said that the ordering of Arda, as to the placing and courses of its parts, was disarrayed by Melkor, so that the Earth was at times drawn too near to the Sun, and at others went too far off."
And at last this is a quote referring to Melkor in his prime :
"In the latter the Fall of Man is subsequent to and a consequence (though not a necessary consequence) of the 'Fall of the Angels' : a rebellion of created free-will at a higher level than Man; but it is not clearly held (and in many versions is not held at all) that this affected the 'World' in its nature: evil was brought in from outside, by Satan. In this Myth the rebellion of created free-will precedes creation of the World (Eä); and Eä has in it, subcreatively introduced, evil, rebellions, discordant elements of its own nature already when the Let it Be was spoken. The Fall or corruption, therefore, of all things in it and all inhabitants of it, was a possibility if not inevitable. Trees may 'go bad' as in the Old Forest; Elves may turn into Orcs, and if this required the special perversive malice of Morgoth, still Elves themselves could do evil deeds."
So I am pretty sure he can't do shit against prime Melkor.
Since we are talking about Melkor in his prime here, he takes this HANDS DOWN! He doesn't need a physical form and is literally immortal. He has infinite stamina and infact fought relentlessly with the Valar for 14.373 years and was able to overpower them all at once and only when Tulkas joined the fight was he not able to keep up. He can destroy continents, dry up seas, create entire mountain ranges (the Misty Mountains, one of the largest mountain ranges in Middle-Earth, which is literally 900 miles long, was created during the Years of the Trees by Melkor when he had long fallen from his prime), volcanoes etc.
A weaken Melkor's scream, literally shook the entire earth and tore rocks asunder! Literally Melkor could destroy the whole planet if the Valar and Eru did not intervene, and this is dimished Melkor we are talking about!
"Melkor could do nothing with Arda, which was not from his own mind and was interwoven with the work and thoughts of others: even left alone he could only have gone raging on till all was levelled again into a formless chaos."
Melkor not in his prime literally did this:
"Also some of the Wise have said that the ordering of Arda, as to the placing and courses of its parts, was disarrayed by Melkor, so that the Earth was at times drawn too near to the Sun, and at others went too far off."
And at last this is a quote referring to Melkor in his prime :
"In the latter the Fall of Man is subsequent to and a consequence (though not a necessary consequence) of the 'Fall of the Angels' : a rebellion of created free-will at a higher level than Man; but it is not clearly held (and in many versions is not held at all) that this affected the 'World' in its nature: evil was brought in from outside, by Satan. In this Myth the rebellion of created free-will precedes creation of the World (Eä); and Eä has in it, subcreatively introduced, evil, rebellions, discordant elements of its own nature already when the Let it Be was spoken. The Fall or corruption, therefore, of all things in it and all inhabitants of it, was a possibility if not inevitable. Trees may 'go bad' as in the Old Forest; Elves may turn into Orcs, and if this required the special perversive malice of Morgoth, still Elves themselves could do evil deeds."
So I am pretty sure he can't do shit against prime Melkor.