Regef Hill is the first prince of Eldyme Empire who aims to become the next Emperor. In contrast to his angelic demeanor and handsome face, he's a person whose cruel disposition is unmatched.

Spoiler

Since Regef was raised as a depraved child deprived of love and affection, he has a twisted personality which turned him into an utter tyrant in his past life. Regef is also highly possessive and power-hungry since the Emperor always warned him that everything he has could be taken away in an instant if he doesn't have power and authority, and hence he always gets angry when someone tries to take anything he covets. He's also very cunning and manipulative as shown when he manipulates and uses the past Kayena as a marionette for his own selfish desires, and does anything he can to achieve his goals even if it means using others as his pawns. He's also a short tempered person who doesn't hesitate to kill others as shown when he proceeds to kill Lydia after she enrages him, and has the habit of breaking nearby objects while throwing tantrums when he's angry. Despite this, he has a soft spot for those who genuinely care about him like the current Kayena, but he inadvertently ruins/hurts them because of his possessiveness and selfish desires.