The sinful "angel of the oath." His original name was Biqa, meaning "good person."
He attempted to coerce Michael to tell him the sacred name of God, but was denied. After the Fall, he was given the name Kazbiel, "he who lies to God."
Kazfiel is the true identity of the woman who broadcasts prayers and messian teachings from Tokyo Tower. After the Basilica becomes available, the Hero can visit the tower and will be asked by the broadcaster if he believes God's help is needed. If he answers no, or is Chaos-aligned to begin with, then the woman transforms into Kazfiel and attacks him.