Seth, in Ancient Egypt mythology, is the embodiment of numerous divine roles.
Yamana knows him, not because Seth is the enemy worshiped by the people of the City of the Sun, but because through the system learning in the outside world, she learned about most of the myths of Ancient Egypt.
Yes, myths... In the eyes of people in the outside world, these are just mythological stories, many of which even carry an element of fun—yet in Yamana's view, it's evidently real... right here in this City of the Sun.
Seth... Seth!
Yamana instinctively looked at the hawk-headed humanoid Pharaoh guarding her side, her expression once again stirred, "Hawk-headed humanoid... Hawk-headed, the symbol of Horus... I should have realized it sooner. But why... why is it Father?"
