Klara Gibson

"Klara Gibson? What the heck is that!? She's a female member of the Belkan Grey Men who was disguised as Hilda Berg and being responsible for the murder of Saraquiel Applebury before she got resurrected! I knew it. She's a murderer. A demonic murderer. I hope she'll pay for this."

--Su Ji-Hoon, Retribution For Angelic Heaven

Klara Gibson is a member of the Belkan Grey Men that she is the one who disguised as Hilda Berg and responsable for killing Saraquiel Applebury before Saraquiel's resurrection.

She would be appeared that she will disguise as Hilda Berg to kill Saraquiel Applebury that it can frame real Hilda Berg

However, she was captured and punished by the heaven angels after they resurrected and made Saraquiel being good and become a heaven angel who can wield Angelic Alliance.