In the end, Duncan couldn't figure out exactly what the "Scion" was.
The Goat Head was vague about it and seemed to be so because it itself didn't know the specifics of these ancient beings that lurked on the fringes of the civilized world. As for Duncan, he could only piece together a little concept from the limited clues—
The Scions were products of ancient times, and they harbored a hatred for the modern world. They possessed strange and dangerous powers, staying hidden and low-profile in the shadows. Aside from the Scions of the Sun, other Scions almost never appeared in the civilized world but instead threatened the safety of explorers in the borderlands.
And among all this information, there was a particularly intriguing point:
The Scions of the Sun seemed to be able to disguise themselves as humans—only the transcendent beings of the Church could distinguish the disguised Scions of the Sun from ordinary people.