Nephilim (Race)

''Faas looked up in horror to see a dark figure in the blinding light. But as it turns out she wasn't dark at all. It took his eyes a few moments to adapt. The large white wings, the glowing white halo right above her head... And those light blue, glowing runic eyes. He saw now why the mortals of Toriel all considered the angels to be gods. This being was simply too surreal - even by magical standards.''

-Faas Mir in The Wars of Blood

Creation
The Nephilim started out as an experiment by the Prometheans to merge mortal lifeforms with draconic without creating a demigod. Eventually they were perfected and put to use as guardians of their separate realms. Each planet with an Odin Vault had a small number of these so called 'angels' on them, around 40-100 depending on the world.