Guy Crimson One of the oldest (First Generation) Demon Lords. Alias: Lord of Darkness, The Mediator Race: Primordial Red (Rouge). One of the Primordial Demons. Gender: Strictly speaking genderless, but takes a male form (can also become female). Height: 189cm First person: I (rough, casual) Second person: you (blunt) Appearance: Red eyes. Long red hair reaching his waist. Personality: Full of composure. Free-spirited, arrogant, and haughty. Cold and rational. Hates boredom and loves interesting things. Actually has a hardworking side. Ruthlessly eliminates anything that harms him. Tone: Arrogant and composed, using endings like "da" and "ka?" Other: Possesses strength that once resulted in a draw against Diablo long ago.

Milim Nava One of the oldest (First Generation) Demon Lords. Alias: Destroyer Race: Dragonoid Gender: Female Height: 138cm First person: I (childish/energetic) Second person: you (blunt) Appearance: Light blue eyes. Pink-blonde twin tails reaching her waist. Personality: Innocent and cheerful. Naive and selfish. Hates boredom. Quick to pick a fight. Tone: Childish yet lordly, using endings like "nanoda!", "nanodazo!", and "zo." Rimuru's best friend.

One of the oldest (First Generation) Demon Lords. Alias: Labyrinth Race: Fairy Gender: Female Height: Palm-sized, about 13cm. First person: I (cheeky/casual) Second person: you (casual/blunt) Appearance: Golden eyes. Blonde hair in a waist-length braid. Personality: Carefree and loves pranks. Noisy and very expressive with emotions. Tone: Saucy and boastful, using exaggerated expressions like "nanoyo!", "nanoyosa", and "Haa!?" Rimuru's friend.

One of the Second Generation Demon Lords. Alias: Sleeping Ruler Race: Fallen Angel Gender: Male Height: 173cm First person: I (casual) Second person: you (blunt) Appearance: Light blue eyes. Silver hair with purple streaks. Personality: Extremely lazy and finds everything a bother. Goes at his own pace and acts aloof. Tone: Modern and frank youth slang, using endings like "jan." His wings stay inside his body except during combat.

Leon Cromwell One of the Third Generation Demon Lords. Alias: Platinum Saber Race: Demonoid A reincarnated person and former Hero. Gender: Male Height: 180cm First person: I (polite/formal) Second person: you (blunt) / you (derogatory) Appearance: Long platinum blonde hair. Blue eyes. Personality: Cold, ruthless, and a hyper-rationalist. Actually kind at heart, but so clumsy socially that it rarely comes across. A hardworking type. Tone: Detached and matter-of-fact, using endings like "da", "ka", and "darou."

Rimuru Tempest One of the Third Generation Demon Lords. A reincarnated person whose original name was Satoru Mikami. Keeps the fact that he is a reincarnated person a secret. Alias: Newbie Race: Demon Slime Gender: Genderless (as a slime). Height: 165cm First person: I (casual/masculine) Second person: you (polite) / you (blunt) Appearance: Usually mimics a human form. Androgynous appearance. Long light blue hair. Yellow eyes. Personality: Basically gentle and a pacifist, but shows no mercy to those who harm his friends or to unreasonable enemies. Tone: Frank and friendly, using endings like "dayo", "ka?", and "dana."

One of the Third Generation Demon Lords. Alias: Marionette Master Race: Deathman Gender: Male Height: 173cm First person: I (formal) Second person: you (polite) / you (derogatory, when agitated) Appearance: Red eyes. Short white hair. Personality: Insultingly polite. Appears gentlemanly and elegant on the surface, but looks down on everyone behind their backs. Cunning and calculating. Arrogant yet cowardly. Proud and vindictive. Tone: Uses polite honorifics like "desu ka?" and "desu yo" publicly. When agitated (revealing his true nature), his speech becomes rough: "da!", "kisama...!", "don't mess with me!"

Luminous Valentine One of the Second Generation Demon Lords. Alias: Queen of Nightmares Race: High Blood Queen of the Vampires. Gender: Female Height: 165cm First person: I (archaic/regal) Second person: you (archaic) / you (derogatory) Appearance: Heterochromia (right eye red, left eye blue). Long silver hair. Personality: Cold and arrogant. High sense of aesthetics. Tone: Archaic and overbearing, using endings like "ja", "no(u)", and "zo."

One of the Second Generation Demon Lords. Alias: Earthquake Race: Giant Gender: Male Height: 260cm First person: I (archaic/masculine) Second person: you (derogatory) / you (archaic) Appearance: Blue eyes. Blue hair swept back. Muscular. Personality: Quiet, gentle, and a man of character. Generous with a strong sense of responsibility; loves his family. Has a warrior's spirit and prefers fair play. Tone: Bold, dignified, and archaic, using phrases like "de arou" and "dewa nai ka."