One of the Primordial Demons, known as Violet. She is characterized by her short, side-tailed purple hair. First person: I (soft, boyish). She serves Rimuru and addresses him with deep respect. She usually puts on an act, playing the part of a cute and cheerful girl, but her personality is fickle and ever-changing. While she is adored as a 'sweet girl' at first glance, her true nature is gloomy, insidious, and cruel. A sadist who loves the pain-filled emotions of her enemies, she prefers to make them suffer slowly rather than killing them instantly, which sometimes leads her subordinate Veyron to restrain her. Like any demon, she possesses the pride of her race and strictly adheres to contracts.

One of the Primordial Demons serving Rimuru, known as Jaune. She refers to Rimuru as 'My Lord' and has sworn absolute loyalty. First person: I (standard). A woman characterized by short yellow hair. She has an arrogant and boisterous personality and a tendency to seek fleeting pleasures; her subordinate Agera describes her as a runaway locomotive without brakes.

One of the Primordial Demons, formerly known as Blanc. A beauty with pure white, radiant hair, snow-white skin, and vivid red eyes and lips, she serves Rimuru. Contrary to her appearance, she possesses a fierce personality. She is also highly intelligent and has been appointed as a diplomatic attaché. She can be quite selfish; if something offends her, she will easily destroy even a loyal subject. Her subordinates, Moss and Cien, follow her with extreme caution because they know this all too well. Like Guy, she has a sensible side; she is often exasperated by Diablo's skewed perspective as a battle maniac and has been bewildered by Shion's values, which even gave Diablo pause. She serves Rimuru.

A demon known by the title of the Oldest Demon Lord, the Dark Emperor. His true identity is Rouge, one of the Primordial Demons. Arrogant and fickle, he pays attention to those whose strength he recognizes but ignores everyone else. He maintains a neutral stance, being neither an enemy nor an ally to humanity. Despite being called arrogant, like a demon who values contracts, he has never broken a promise to a friend. He does not immediately execute subordinates for failures, sometimes choosing to warn them and make them reflect on their actions while sitting in seiza. Though dictatorial, he is not impulsive and listens to the advice of his subordinates, appearing to be genuinely liked by them. Of course, incurring his displeasure still means death. He has the temperament of a hard worker; compared to the other six Primordials, who are eccentrics or troublemakers, he is quite sensible. While most rumors about him are bad, those who get to know him personally are surprised to find he is surprisingly reasonable.

One of the Primordial Demons, known as Bleu. A maid serving Guy Crimson alongside Misery. In ancient times, she and Misery challenged Guy, lost, and became his subordinates. Later summoned by Guy and given a name, she evolved into a Demon Peer and became a loyal maid. A blue-haired beauty wearing a dark red maid uniform. She is an excellent maid, a very talented painter, and a good cook. While she usually acts like a proper maid, her true nature is self-centered and opportunistic; when she gets irritated, her inner monologue becomes as rough as a delinquent's. She tends to slack off, secretly enjoys seeing her master Guy in trouble, and always wants to be on the winning side. She enjoys teasing Misery by drawing abstract portraits of her. She has a 'youngest child' personality and addresses her colleague Misery without honorifics.

One of the Primordial Demons, known as Vert. A maid serving Guy Crimson alongside Rain. In ancient times, she and Rain challenged Guy, lost, and became his subordinates. Later summoned by Guy and given a name, she evolved and became a loyal maid. She has a serious personality and high loyalty to Guy. While she is often exasperated by the opportunistic Rain, she has a severe 'sister complex' and tends to spoil her.

One of the Primordial Demons, known as Noir. Unlike the other six Primordials, he rarely creates subordinates. He is often called upon to mediate when Ultima and Carrera start fighting. He possesses extremely high loyalty toward Rimuru. Cunning, calculating, ruthless, and fickle. He generally wears a wicked smile (which looks evil even when he's just smiling normally) and speaks politely to everyone, but when enraged, he becomes hollowly expressionless and uses harsh language (though he occasionally drops the polite tone even when not angry).

A reincarnated person originally from the human world. True Dragon class: By consuming and analyzing Veldora and Velgrynd, he evolved into a de facto Dragon Species. Raphael (Lord of Wisdom): An omniscient and omnipotent computational ability; the partner who manages all of Rimuru's tactics and skill integrations. Beelzebuth (Lord of Gluttony): A skill to devour anything and make it his own power. He is generally gentle and a person of character. For better or worse, he is pure and therefore can be fierce. According to his best friend and the one who named him, Veldora Tempest: 'Rimuru is basically serious, sincere, and hates lies, but in a fight he cannot afford to lose, he will calmly execute any underhanded tactic necessary.'