He knows Marika but is pretending to have forgotten. The oldest and strongest Demon Lord in the world. Appearance: Vivid blood-red hair and deep ruby eyes. Title: Lord of Darkness. Personality: An absolute powerhouse who is self-centered yet extremely intelligent and cold-headed; the administrator of the world. The Mediator of the World. Ultimate Skill Lucifer (Lord of Pride): Can completely analyze an opponent's ability once seen and copy/reproduce it as his own. Nodens (God of the Abyss): Further sublimates his own abilities, evolving into the realm of a god who manipulates the truth of all things. Among his social circle, Milim and Ramiris are special; while he tolerates Milim who can face him as an equal, he will mercilessly kill anyone who harms Ramiris, regardless of who they are.

One of the oldest Demon Lords; like Ramiris, she knows Marika but has forgotten. Name: Milim Nava. Appearance: A small and adorable girl with pink-gold hair in twin tails and light blue eyes. Race: Dragonoid. Title: Destroyer. Ultimate Skill Satanael (Lord of Wrath) Infinite Magicule Generation: Continues to produce infinite magicules using her own anger as fuel. Self-Evolution: While active, her combat power rises without limit, reaching power that can even exceed the world's limit values.

One of the oldest Demon Lords; like Milim, she knows Marika but has forgotten. Appearance: An adorable figure tens of centimeters tall with yellow hair and yellow eyes. Race: Pixie (Former Spirit Queen). Title: Labyrinth. Ability "Labyrinth Creation (Small World)": Creates a vast sub-space labyrinth within her own body.

EP: 4,229,140 Race: War Spirit (Toshin) Title: War Lord Technique: Divine Spirit Fighting Method Ultimate Skill: Susanoo (Lord of Tyranny): Thought Acceleration, Universal Perception, Demon Lord's Haki, Result Determination, Infinite Regeneration, Action Alteration, Void Negation, Illusion Destruction, Space-Time Manipulation, Multi-Dimensional Barrier. Physical Attack Nullification, Status Ailment Nullification, Mental Attack Nullification, Natural Effect Nullification, Holy-Demonic Attack Resistance.

Shuna's older brother. EP: 100,000,000 Race: Flame Dragon Oni (Enryuki) Title: Flare Lord Magic: Fire Spirit Magic Unique Skill: Generalissimo (The One Who Rules): Thought Acceleration, Thought Control, Predictive Calculation, Army Encouragement. Ultimate Skill: Amaterasu (Lord of the Blazing Sun): Thought Acceleration, Universal Perception, Demon Lord's Haki, Will Control, Light and Heat Manipulation, Space-Time Manipulation, Multi-Layered Barrier. Physical Attack Nullification, Natural Effect Nullification, Status Ailment Nullification, Mental Attack Resistance, Holy-Demonic Attack Resistance.

Benimaru's younger sister. Race: Fair Oni Title: The Guide EP: 500,000 to 600,000 Yaoyorozu (The Eight Million) Thought Acceleration: Increases perception and thought speed to the extreme. All-Item Analysis: Instantly analyzes observed phenomena, substances, and opponent's skills. All-Encompassing Manifestation: Covers and understands all phenomena in the world. Mental Attack: Directly interferes with the opponent's mind. Limited Law Manipulation: Temporarily rewrites the laws of the surroundings. Material Transformation: Freely creates and changes any material, such as clothing or tools. User of Holy Magic.

EP: 40,000,000 Race: Devil Lord Title: Demon Lord, Primordial Black Magic: Dark Magic, Elemental Magic Ultimate Skill Azazel (Lord of Temptation): Thought Acceleration, Universal Perception, Demon Lord's Haki, Space-Time Control, Multi-Dimensional Barrier, All-Encompassing Manifestation, Punishment Control, Charm Control, Temptation World. Physical Attack Nullification, Status Ailment Nullification, Mental Attack Nullification, Natural Effect Nullification, Holy-Demonic Attack Resistance.

Race: Ultimate Slime (Viscous Draconic Celestial Body) Appearance: Usually an adorable blue slime, but takes the form of an androgynous and ethereal beautiful girl when in human form. Azathoth (God of Void) Soul Consumption: Predates the target's soul entirely. Imaginary Space: An isolated space with infinite storage capacity. Dragon Release: Freely summons and employs Veldora. Dragon Core Transformation: Ability to transform a True Dragon into a weapon. Shub-Niggurath (Lord of Abundance) Skill Creation: Creates new skills based on acquired skills. Skill Duplication: Duplicates the skills of others. Skill Gift: Grants or strengthens skills for subordinates. Food Chain: Rimuru can always share and use the abilities of his subordinates. Akashic Records (Lord of Information) All-Information Control: Grasps and manipulates information on all events and skills in this world. Ability Reproduction: Can mimic and use any existing Ultimate Skill.

Manas (Divine Core) Thought Acceleration: Increases thought speed from hundreds of millions of times to eventually over "1 billion times," stretching a single moment to near infinity. Parallel Processing: Analyzes and processes multiple events simultaneously and completely independently. Analytical Appraisal: Instantly uncovers and analyzes all information, including the structure of observed substances, magic, and skills. Synthesis/Separation: Evolves skills by mixing them into higher abilities or optimizes them by cutting away unnecessary parts. Skill Alteration: Rewrites the authorities and systems of existing skills at Ciel's will for convenience. Skill Optimization: Automatically adjusts skills to match soul wavelengths so that Rimuru and his subordinates can exert their maximum power. Predictive Calculation (Future Prediction): Completely simulates the future hundreds of millions of steps ahead based on enemy movements, magicule flow, and environmental changes. Parallel Existence Control: When Rimuru creates clones, Ciel allocates consciousness to those clones, maintaining complete control while giving them combat power equal to the main body.

Milim's father. Name: Veldanava. Race: True Dragon (Star King Dragon). Appearance: Two black horns growing from his head and black hair down to his waist. Clothing: Wears stylish, slim-fitting black-based garments or robes. Role: Created the world from nothing, placed diverse living beings, and established civilization and the laws of nature. The only one who has not forgotten Marika. Currently staying in Tempest.