[Belegorn]

Supposing Melkor did create Orcs from some sort of process he engaged in with the Elves, did he have the power to change the Doom of a species? For example, Elves have life in Arda so long as it endures unless killed by weapons, or death from grief. This would mean the Orcs are immortal in this sense as well. I believe there are various places where it is mentioned that none has the power to do this. In The Debate of Finrod and Andreth Finrod does bring this up and it seems like he quakes with fear at the thought that Melkor could hold such power. I also wonder would an Elf even hold on so long to be twisted in such a manner to become an Orc and not die from grief instead? Melkor is so much stronger than any one of his contemporaries and perhaps he was a bit beyond their own understanding as well?

The idea of Melkor harvesting his essence to create mini-mes seems like it could work. He's not necessarily creating life but in some manner using chunks of himself as independent entities that do have some ties to him. Perhaps he found a way to get around the Flame Imperishable in this manner. This would seem to fit in well with Tolkien's idea of the Morgoth in Myths Transformed as Pitchwife has quoted. Melkor dispersed.