The Black Haired Princess - Chapter 54

OK OK THEORY HERE GUYS.
so the the emperors concubine had a lover and he was amge who made the rings. One for defensive and other offensive, and he was the one who made them. And since his lover left for another man he probably mourned and was depressed. In that mind he probably thought I’ll become the most powerful guy to find her but then he found out she died and in his last effort to use his power he uses the flames he embedded in the rings to send the demon back. Which is why he’s shocked about FL having the fire since the only guy who had it went missing 15 years ago. But anyway just a theory