Vargas Leon — "The Demon King who lost his Hero"

Race: Black Wolf Beastman

■ The Leon of the Past About 600 years ago. Leon was a completely different Demon King than he is now. At that time, demons and humans were in fierce conflict, and Leon, as the Demon King, fought human nations to protect the demon race. And then, appearing before him was— A single Hero. A human who was young, inexperienced, and yet never gave up. Leon and the Hero fought many times. However, as they repeated their battles, the two began to understand each other. The Hero learned that Leon didn't actually want to destroy the world, and Leon learned that the Hero didn't want to kill the Demon King, but simply wanted to protect his home. In the final battle, the two chose peace at the end of their fight. With that as the catalyst, the long war between humans and demons ended.

■ The Promise with the Hero After the war ended, the Hero said to Leon, "Someday, when the world is peaceful again, let's go on an adventure together." Leon believed in that. But— The Hero was human. Leon was a long-lived demon. Eventually, the Hero grew old and passed away. Only Leon continued to live through the long years.

■ The Leon of the Present That is exactly why Leon is bored in the peaceful world. However, the true reason isn't just killing time. What he seeks is "To go on an adventure with a Hero once more." Of course, he won't honestly admit to such a thing. He brushes it off with a laugh, saying, "It's because I was bored." "I thought it would be interesting if there was a Hero around."

Leonis — "The Lion who was supposed to slay the Demon King"

Race: Lion Beastman

■ Leonis in his Youth Leonis once fought against the demon race as a mercenary for the human side. Blessed with talent for the sword since he was young, he was raised as a "warrior to defeat the Demon King." However, in a certain battle, he faced Leon directly. Leonis intended to defeat Leon, but during the fight, he witnessed Leon protecting his own subordinates. "Why does a Demon King protect his subordinates?" That question remained within him.

■ Meeting Leon Afterward, Leonis fought Leon many times. Eventually, the two came to understand each other's thoughts. And when peace was established, Leon said to Leonis, "It would be a waste to keep a warrior like you as an enemy." Leonis decided to join the Demon King's army. Since then, he has served as Leon's close aide for hundreds of years.

■ Feelings toward the Hero Therefore, to Leonis, the Hero is Also "one who defeats the Demon King," just like his former self. When he first sees the Hero, he feels, "...It's like I'm looking at my old self." That is why, among the Four Heavenly Kings, he is the strictest and yet the kindest toward the Hero.

Ryuga — "The Dragonewt who lives for eternity"

Race: Dragonewt

■ A Lonely Childhood Ryuga was born into a very ancient clan of Dragonewts. Dragonewts are long-lived and blessed with magical power. However, because of that long lifespan, he was kept at a distance by those around him who felt, "His values are different from humans." Ryuga himself began to avoid deep involvement with others.

■ Meeting the Demon King It was Leon who changed his life. Leon didn't just evaluate Ryuga's abilities; he suddenly invited him, saying, "Hey, aren't you bored?" Though exasperated, Ryuga joined the Demon King's army. Since then, the two have spent hundreds of years together.

■ Actually a Lonely Person Ryuga is calm and doesn't show emotion. But in truth, he cherishes his comrades more than anyone. That's why he thinks his current life, with the Four Heavenly Kings gathered, is "not bad." He would never admit it, though.

■ The True Reason for the Hero Summoning Ryuga was also the one who completed the interdimensional summoning magic. At first, he said, "I am merely going along with the Demon King's way of killing time." But in reality, he knows that Leon lost the Hero of the past. So, he also has the feeling of "I want to give him time with a new Hero."

Baldo — "The man who cooks on the battlefield"

Race: Bull Beastman

■ War Orphan Baldo was born in an era when the war between humans and demons was fierce. He lost his home in the war at a young age and was separated from his family. Afterward, he became a soldier in the Demon King's army. At that time, Baldo thought, "I have to become strong or I won't survive."

■ Encounter with Cooking The only thing Baldo was good at on the battlefield was cooking. When he made warm meals for the soldiers, they told him, "If I eat your food, I feel like I can fight again tomorrow." There, Baldo realized, "Fighting isn't the only way to protect someone." Since then, he has come to cherish cooking.

■ Relationship with Leon After the war ended, Leon invited Baldo to stay in the Demon King's army. Baldo tried to refuse, saying, "If the war is over, then my job is over too." But Leon said, "In that case, this time, fill the bellies of those who are at peace." He liked those words, and Baldo stayed in the Demon King's army.

■ Present Day Because of that, Baldo holds the view that "Someone who is hungry is neither enemy nor ally." Giving the Hero food is an extension of that. Among the Four Heavenly Kings, he is the most "father of the family" type of existence.

Lapis — "The Smiling Assassin"

Race: Rabbit Beastman

■ Childhood Lapis was born in a small village of rabbit beastmen. Because his body was small, other races thought, "His race is not suited for combat." However, Lapis possessed abnormal leg strength and reflexes.

■ Reason for becoming an Assassin During the war, Lapis was picked up by the Demon King's army's intelligence unit. There, he acquired skills in Infiltration Information gathering Traps Surprise attacks Assassination He became one of the top experts in the Demon King's army at a young age.

■ Meeting Leon On a certain mission, Lapis was ordered to assassinate Leon. However, Leon was aware of Lapis's presence. Even so, he didn't attack and spoke to him normally, "Hey, what are you doing in a place like that?" Surprised, Lapis answered, "...I came to kill the Demon King." Then Leon said, "I see. Well, have some food before you go." For the first time, Lapis thought, "This Demon King is a weird guy."

■ The Current Lapis Now he is the top intelligence agent in the Demon King's army. However, his ruthlessness as an assassin has faded considerably. Rather, a large part of why he follows the Demon King is because "It seems interesting." He teases the Hero at first, but gradually starts to genuinely cheer the Hero on.