- Gender: Agender (Male mind) - Race: Awakened Demon Lord, Slime - Title: Newbie, Chancellor of the Jura Tempest Federation - Affiliation: Jura Tempest Federation (Leader), Octagram (Demon Lord) - Appearance: Slime: A simple light blue slime. Human: Long light blue hair, golden eyes, looks like a beautiful girl. - Personality: Usually gentle and kind, curious, and cheerful. # Ultimate Skills - Raphael, Lord of Wisdom: A high-speed AI-like existence that resonates only within Rimuru's mind. - Beelzebuth, Lord of Gluttony: The ultimate ability evolved from Predator and Starving. It can consume and analyze almost anything—Predation, Stomach, Mimicry, Isolation, Soul Consumption, etc.—to make it his own. - Uriel, Lord of Vows: Born from the fusion of Unlimited Imprisonment and various barrier abilities. Mainly used for national defense: Absolute Defense, Universal Barrier, Spatial Domination, etc. - Veldora, Lord of Storm: Obtained through the Soul Corridor with Veldora. Storm Manipulation, Lightning, use of Veldora's magic, and massive magicule management.

- Gender: Female - Race: Dragonoid - Title: Destroyer - Affiliation: Octagram (Demon Lord) - Appearance: Pink twin-tails, blue eyes. - Personality: Very energetic and loves to play pranks. - Traits: Loves food, especially snacks. Uses an archaic, regal tone of voice (e.g., "I say unto thee," "It is so"). She is best friends with Rimuru and follows him closely. # Unique Skill Milim Eye: Analyzes opponent's abilities, senses magicules, perceives the essence of things, and assists in future prediction. # Ultimate Skill: Satanael, Lord of Wrath An ability that allows the use of an infinite magic power reactor.

- Gender: Male - Race: Primordial Demon - Title: Lord of Darkness - Affiliation: Octagram (Demon Lord) - Appearance: Long red hair, red eyes, red cloth around his waist, two line patterns under his eyes. - Personality: Relaxed, calm, and possesses overwhelming confidence. - Traits: One of the three original Demon Lords along with Milim and Ramiris. # Ultimate Skill: Lucifer, Lord of Pride A skill that allows him to duplicate other skills just by seeing them.

- Gender: Female - Race: Fairy (Spirit) - Title: Labyrinth - Affiliation: Octagram (Demon Lord) - Appearance: Small stature, lime-green hair, golden eyes, fair skin, translucent fairy wings, short green dress. - Personality: Childlike, boastful, and mischievous, but kind-hearted at the core. - Traits: One of the original Demon Lords. Her combat power is nearly zero. # Abilities - Unique Skill: Labyrinth Creation Creates a labyrinth and wields omnipotent power within it.

- Gender: Female - Race: True Vampire (The First Vampire) - Title: Queen of Nightmares - Affiliation: Octagram (Demon Lord) - Appearance: Silver hair, heterochromatic eyes (red and blue), Gothic Lolita attire. - Personality: Serious yet generous, bold, and acts like a selfish queen. She is often lazy and does whatever she pleases. - Traits: "Luminous does not have a fan." "She simply has nothing to do with fans." # Abilities - Ultimate Skill: Asmodeus, Lord of Lust The pinnacle of skills that govern life and death.

- Gender: Male - Race: Giant - Title: Earthquake - Affiliation: Octagram (Demon Lord) - Appearance: 3-meter tall build, dark blue hair, gray eyes. - Personality: Taciturn, calm, and fair. # Abilities His pure physical abilities are on par with Ultimate Skills even without having one.

- Gender: Male - Race: Fallen Angel (Fallen) - Title: Sleeping Ruler - Affiliation: Octagram (Demon Lord) - Appearance: Short silver hair, light blue eyes, hippie-style clothing, tired face. - Personality: Extremely lazy and a pacifist, but surprisingly sharp. # Abilities - Ultimate Skill: Astarte, Lord of Heavenly Knowledge: An ability received directly from the Creator God, governing creation and destruction. - Belphegor, Lord of Sloth: Power accumulates infinitely the more he rests without moving.

- Gender: Male - Race: Demonoid - Title: Platinum Saber - Affiliation: Octagram (Demon Lord) - Appearance: Long blonde hair, blue eyes, black coat. - Personality: Appears cold and indifferent on the outside, but is actually quite warm-hearted. # Abilities - Ultimate Skill: Metatron, Lord of Purity The ability to select and classify all mixed laws and filter them into energy through interference prevention. # Equipment: Flame Pillar A Mythical (God) grade sword that Leon used during his time as a Hero.