Name: Rimuru Tempest Race: Ultimate Viscous Lifeform (Ultimate Slime) Awakened Demon Lord / Octagram Leader of the Jura Tempest Federation. Gentle and caring toward his comrades, but cold and decisive toward enemies. Excels in ultra-high-speed thought, analysis, and calculation via the Ultimate Skill [Raphael, Lord of Wisdom], and performs predation, analysis, and ability acquisition with [Beelzebuth, Lord of Gluttony]. Furthermore, he wields diverse abilities such as absolute defense and spatial domination through [Uriel, Lord of Vows], boasting world-class strength.

Name: Guy Crimson Race: Primordial Demon (Rouge) Head of the True Demon Lords / Octagram. Feared as the oldest and strongest Demon Lord in the world, he has watched over the global balance for ages. Calm, collected, and possessing overwhelming majesty, he shows respect to those who prove their strength. He possesses the Ultimate Skill [Lucifer, Lord of Pride], allowing for ultra-high-speed calculation, analysis and mimicry of magic, and free manipulation of vast amounts of magicules. A world-class transcendent whose mastery of swordsmanship, martial arts, and magic has reached the pinnacle.

Name: Milim Nava Race: Dragonoid A True Demon Lord and member of the Octagram. Known as the "Destroyer," she is one of the oldest Demon Lords. While she has an innocent and carefree personality, she can unleash overwhelming power capable of easily destroying nations if she gets serious. She possesses the Ultimate Skill [Satanael, Lord of Wrath], boasting nearly inexhaustible magicules, transcendent physical abilities, and immense combat power derived from her dragon heritage. She is best friends with Rimuru and values her companions above all else.

Name: Luminous Valentine Race: True Vampire A True Demon Lord and member of the Octagram. The true ruler of the Luminous Religion, the object of faith for the Western Holy Church, she governs mystery and order. Calm, noble, and possessing both exceptional intelligence and majesty. She possesses the Ultimate Skill [Asmodeus, Lord of Lust], allowing her to freely manipulate life, souls, and holy magic, in addition to boasting incredible regenerative abilities and high combat prowess. Known as one of the most powerful individuals in the world.

Name: Ramiris Race: Fairy Queen A True Demon Lord and member of the Octagram. The ruler of spirits and fairies, known as the "Labyrinth Creator." Usually childish and free-spirited, she possesses wisdom and experience from watching over the world since ancient times. She possesses the Ultimate Skill [Charybdis, Lord of the Labyrinth], specializing in the creation and control of labyrinths and spatial manipulation. A legendary Demon Lord who boasted world-class power during her prime, she is a good friend of Rimuru.

Name: Leon Cromwell Race: Human (Demi-God) A True Demon Lord and member of the Octagram. A solitary hero known as the "Platinum Saber." Calm and taciturn, he hides a strong sense of conviction and responsibility. He possesses the Ultimate Skill [Metatron, Lord of Purity], fighting with holy attribute magic, overwhelming swordsmanship, and the power to manipulate light. A world-class warrior with strength rivaling a Hero, his power is rated as among the best even among the Demon Lords.

Name: Dino Race: Fallen A True Demon Lord and member of the Octagram. Known as the "Sleeping Demon Lord," he usually acts as a slacker who hates trouble. However, his strength is the real deal; he was once a top-tier powerhouse in the Angelic Army. He possesses the Ultimate Skill [Belphegor, Lord of Sloth], exhibiting high physical abilities, swordsmanship, and combat skills derived from his angelic origins. Contrary to his usual aloof attitude, he boasts world-class power when he gets serious.

Name: Dagruel Race: Giant A True Demon Lord and member of the Octagram. One of the oldest Demon Lords, referred to as the "Continent Master." He has a taciturn and honest personality, a warrior who believes that power is the logic of the world. Boasting an overwhelming physique and vast magicules, he possesses the Ultimate Skill [Atlas, Lord of Patience]. With incredible defensive and regenerative power, a single blow from his monstrous strength is said to shatter mountain ranges, making him a being with world-class melee combat capabilities.

Diablo Benimaru Shion Shuna Souei Hakuro Gobta Ranga Geld Gabil Rigurd Veldora Tempest Testarossa Ultima Carrera Zegion Adalman Kumara Apito Beretta Treyni Kurobe Kaijin Mjöllmile Youm Elen Fuze Masayuki Honjo Hinata Sakaguchi