DB Vol 5 Part 7

He was an Esper of the Yang family.

“You idiot! Didn't I tell you?! Since the Esper with the Mutant Seed has disappeared, you were to hold off on releasing a statement from the Guide Center!”

Yoon-im's angry voice filled the chairman's office of the Guide Center. Even Seong-hyeon, who had known her for a long time, rarely saw her shouting to the point where the veins in her neck bulged.