I feel we could have the human/'dragon' mix-bloods and other types of humanoids without going sci-fi or having any sci-fi elements in the time period when the guardians reawaken.
It'll be like, the full-blood 'dragons' come and are perceived as foreign spirits or deities by the humans, some mate with humans all over the world, and then depart, leaving behind a bunch of human/'dragon' hybrids capable of slightly different magic than that of the other denizens of the planet.
The magic these hybrids have is slightly stronger and more stable than that of the humans, but they have to eat a lot of food to replenish their magic.
Plus, a lot of legends and other stuff could be applied to these hybrids, such as groups that actively hunt them (because I don't know, that group might feel the existence of the hybrids is an insult to the guardians or something?)
The hybrids would also know about as much about the world/universe as all the humans.
It'll be like, the full-blood 'dragons' come and are perceived as foreign spirits or deities by the humans, some mate with humans all over the world, and then depart, leaving behind a bunch of human/'dragon' hybrids capable of slightly different magic than that of the other denizens of the planet.
The magic these hybrids have is slightly stronger and more stable than that of the humans, but they have to eat a lot of food to replenish their magic.
Plus, a lot of legends and other stuff could be applied to these hybrids, such as groups that actively hunt them (because I don't know, that group might feel the existence of the hybrids is an insult to the guardians or something?)
The hybrids would also know about as much about the world/universe as all the humans.