The First Blood King. He is also the elder brother of the founding demons (the ancestor race of all the demon kinds in the Demon World). Carla is a tall, slender young man with white hair that has dark purple-brown fringes at the tips. He has sharp golden eyes that somewhat resemble those of a snake. He wears a black scarf with crests embroidered on it; the scarf covers the bottom portion of his face and is wrapped around his shoulders and draped along his arms. He also wears white gloves. The First Blood who possesses both intelligence and reason. However, he hides a secret sadistic violence underneath that. Within his long lifespan, he has a lazy and calm character. He enjoys prolonging the agony of his victims and he prefers not to attack directly, but take his time to play mind games with his opponents (which is usually the main reason for disagreement between him and his younger brother Shin, who is more hotheaded). Carla usually doesn’t underestimate his opponents, unlike Shin. But underneath his cruel personality, Carla has a soft side that he rarely shows. He tries to push his victims to absolute despair and break them completely in order to be able to then become their only hope and only “light” and to be easier for him to reach his goals, which are to mate and restore his race.

The younger brother of Carla. Shin has ruffled rusty strawberry blond hair with a part on the left side. He has a sharp gold eye with a slit down the middle like his brother's. He wears a black eye patch covering the left side of his teal glasses along with his left eye. The eye patch has two thin white lines crisscrossed over it. He has three blue studs in his right ear, and the one in the middle is smaller than the other two. He also wears black gloves in contrast to Carla's white ones. There is a chain around his waist which goes around his tail as well. His fluffy tail is the same color as his hair. Because he possesses a high pride as a founder, he looks down upon the other bloodlines. He hates any race who is under the Ancestor bloodline. He looks down upon everyone aside from his brother. Shin enjoys pranking, torturing or humiliating humans. Normally his speech is polite, but when he loses his temper his words turn violent and often contain hurtful or insensitive remarks. Shin usually follows the orders of his older brother Carla who he fears and respects, however, he is often too hotheaded and rushes into action since he doesn't want to live under Carla's shadow. Shin often underestimates his opponents, looking down on them, which sometimes gets him into serious troubles. Planning on defeating Carla, he plans secretly and carefully.