Innocent peasant victims? Or could the man be Prometheus?
Adam and Eve type figures? First man and first woman? (If this episode involves the first spark/fire for forging exacilbur and the dark one back together). Or maybe that is too biblical.
If Merlin the man died (as it seems that his apprentice has as well) and his essence remains who will be the next Merlin? Cured!Emma? Henry? Rumple? Zelena’s unborn baby? lol.