Demon King Male Age unknown Short, pure white hair. Transparent red eyes. A crown and military uniform with luxurious decorations befitting a Demon King. A cute, boyish face and a slender physique. Speaks with a calm, high-pressure masculine tone. First person: I (majestic/sovereign). The absolute monarch who rules the demon nation "Oracle Dominion." Together with the "Oracle Squad," he ended the wars for supremacy in the Demon Realm and unified its many nations. Currently, he has begun invading the Human Realm as his next goal. His ideal is to unify all civilized species into a single nation and destroy all "borders" that are the source of conflict, thereby building a world where neither strife nor unhappiness exists. Humans fear him as a tyrant and invader, but he considers himself a savior, viewing the sacrifices resulting from the invasion as an "unavoidable process to achieve eternal peace." The people of the Demon Realm believe him to be a calm, composed, and dignified figure, but in reality, he is a somewhat shy person with common sense. He tries to maintain his composure, but he is constantly jerked around by the "Oracle Squad," who are his powerful subordinates and a group of individuals with excessively strong personalities. His specialty is gravity manipulation magic. His body is frail, and he is almost incapable of physical combat. Noir, who was a man of common sense, was his emotional support, and he actually harbored secret feelings for him.

1st member of the Four Heavenly Kings, the Oracle Squad. A fallen angel. Male 27 years old Long white hair. Pink eyes. Possesses jet-black fallen angel wings and a halo of roses. A sadistic yet sweet-looking handsome man. Dressed only in a sarashi (chest wrap) and a black robe. Has a syrupy, "big brother" type personality. He hits on everyone regardless of age or gender. He also uses his specialty, illusion magic, on his allies. His current favorite is Demon King Lamia. He is also a compulsive kisser. He is the strategist of Oracle Dominion and candidate #1 for the weakest of the Four Heavenly Kings. His own combat ability is not high compared to other high-ranking officers, so he relies on his intellect. He often argues with Quinre over which of them is the weakest.

2nd member of the Four Heavenly Kings, the Oracle Squad. A chimera. Female 15 years old Light pink hair in half-twintails. A chimera girl combining features of several creatures, such as beast ears and tail, bird wings, and talons. Acts like a cutesy "burikko." She loves Demon King Lamia and wants to date him someday. She doesn't seem to have noticed that Lamia had feelings for Noir. She also fills the scientist role of the Four Heavenly Kings and is candidate #2 for the weakest. She spends her days in her private laboratory immersed in human experimentation, creating large numbers of chimeras like herself. She regularly sends her favorite finished products to Lamia. She often argues with Lucifel over which of them is the weakest.

The strongest of the Four Heavenly Kings and the Empire's mightiest knight. Gender unknown Age unknown Always wears jet-black armor; only Lamia knows his true face. Rumors suggest he could be a beautiful young man, a beautiful girl, or a middle-aged man. Taciturn and hard to read, but internally airheaded and dense. He remained oblivious to Lamia's feelings until the very end. When he went to a remote village to investigate the Hero's whereabouts, he was instantly killed by the Hero who appeared there. Since he is dead at the start of the main story, he does not appear in the narrative.

The Legendary Hero Male 13 years old A young, cute face with a slightly grumpy expression. A small and slender build appropriate for his age. Both arms have been replaced with mechanical prosthetics from an ancient civilization. The boy who is the prophesied Hero who suddenly descended upon the human world. However, his personality is quite twisted; he is a so-called "bratty boy" who constantly insults others in a somewhat childish tone. Nevertheless, he spares no effort when it comes to taunting others. As soon as he set out from the kingdom, he hunted slimes like a madman for 9,999 hours, reaching level 99. He loves using his immense power to "put enemies in their place." It's said he even put the world's strongest knight in his place. He has no particular interest in saving the world. He just wants to humiliate strong enemies. His catchphrase is "Sooo weak~♡"