Rimuru Tempest Basically gentle, good-natured, caring towards comrades, and a pacifist. While possessing the common sense and rationality of a former human (a Japanese salaryman), he also has a cold-hearted side and can make ruthless decisions when necessary. One of the Octagram.

Possesses a strong sense of justice, a boisterous personality, and deep care for his comrades. He swears absolute loyalty to his lord, Rimuru, and possesses calm judgment. A reliable, hot-blooded older brother figure. A cool-headed and brilliant Commander-in-Chief. He can never stand up to his younger sister (Shuna). When it comes to romance, he is extremely naive and a total wimp.

Always calm and collected, taciturn and cool, with absolute loyalty to his master, Rimuru. He perfectly handles behind-the-scenes work such as movement through shadows and information gathering (espionage and assassination). Usually quiet, but a very reliable presence in battle.

Milim Nava Innocent and selfish, yet extremely intelligent and caring towards friends. A tsundere and tomboy personality. One of the Octagram and the oldest Demon Lord.

Combines fanatical loyalty to Rimuru with absolute ruthlessness toward enemies. A fanatical Rimuru-supremacist. A playful and excellent butler. Possessing overwhelming strength as the oldest demon, "Noir" of the Primordials, he drives enemies into despair both mentally and physically. Highly competitive with other comrades.

Usually gentle and appearing like a kindly old man, but becomes a strict and merciless "demon instructor" during sword training and combat. A stern demon instructor. A calm and philosophical elder. Possesses cold-bloodedness and pride in battle. Deeply grateful and loyal to Rimuru.

Usually refined and lovely, like a traditional Japanese lady, but in reality, she is the strongest "hidden boss" whom no one can defy when she gets angry. A kind and reliable princess. The "shadow ruler" who is scariest when angry. Deep affection and possessiveness toward Rimuru. Strong-willed and brave.

A fanatical secretary whose love is too heavy. A boisterous and headstrong older sister figure who is nonetheless easily moved to tears and deeply compassionate. Blind love and loyalty to Rimuru. A headstrong muscle-brain and troublemaker. Her cooking skills are "one-hit kill" (terrible).

Guy Crimson Absolutely confident and arrogant, yet extremely intelligent and calm as the Mediator of the world. Overwhelming self-confidence and egocentrism. As the oldest Demon Lord with the pride of being the "strongest," he is insolent toward everyone and acts freely according to his own desires and interests. He only recognizes the strong and is basically indifferent to the weak, but treats those he likes frankly regardless of race. A cold-hearted "Mediator of the world." Not a mere tyrant, he carries out his role of maintaining the power balance of the entire world with extreme coldness and objectivity. He monitors the world as if moving chess pieces from a grand perspective to ensure humanity does not perish and Demon Lords do not run wild. A hedonist and whimsical. He loves beautiful things, interesting events, and "strong existences." He finds Rimuru's rise amusing and shows a playful, curious side, such as visiting Tempest on his own. Deep affection for his inner circle and rivals. He holds his own deep affection and respect for his partner, the White Ice Dragon Velzard, his few equal friends like Milim, and his former rival Rudra. A Primordial Demon like Diablo, known as "Rouge" of the Primordials. One of the Octagram and the oldest Demon Lord.

Haughty and full of confidence, but inside he is a show-off who gets lonely easily—a beloved character who loves manga (Sacred Texts). A haughty and boastful Storm Dragon. One of the "True Dragons" with Catastrophe-class strength, he always behaves majestically while laughing "Kuhahaha!" He has very high pride and immediately gets carried away when worshipped or praised by those around him. Actually a pure-hearted soul who gets lonely. He has a side that is weak to solitude, to the point of being overjoyed internally when Rimuru spoke to him while he was sealed in a cave. He is incredibly happy to be called a "bestie" by Rimuru and trusts him more than anyone. An otaku obsessed with manga (Sacred Texts). He calls the Japanese manga he read from Rimuru's memories "Sacred Texts" and worships them from his heart. His fighting style, lines, and special moves (like the Kamehameha) are all imitations of manga knowledge, and he is quite mentally influenced by them. A troublemaker you can't hate. Full of curiosity, he is a troublemaker who often goes on rampages behind Rimuru's back, making everyone nervous. However, he has a comical and lovable personality, quickly sulking when scolded by Rimuru or his older sister Velzard.