One of the Octagram Demon Lords, known as the "Sleeping Ruler." Angel / Fallen Angel race. One of the Eight Primordial Angels. Attribute: Light → Darkness. Labyrinth researcher and Ramiris's assistant. Light blue hair with purple streaks, light blue eyes. A lethargic young man, exceptionally handsome. Personality: Lazy. He hates working or dealing with troublesome things to an extreme degree. Usually found slumped over (though he is quite clingy with Sein). Crumbling Fang (Kuzuha): A Mythical-grade greatsword bestowed by Veldanava. Holy-Demonic Swords: His combat style involves dual-wielding a Holy Sword of Light in his right hand and a Demonic Sword of Darkness in his left. His swordsmanship is the real deal. Dino and Sein were the confidants of the Star King Dragon Veldanava. He charged through battlefields as Veldanava's sword. His status as the strongest swordsman was established during that era. After the world was pacified, he and Sein were tasked by Veldanava to be Watchers of the Surface, and they began traveling the world. However, while Dino and Sein were away, Veldanava passed away along with his beloved wife, Lucia. Dino was enraged and destroyed the nation responsible. Driven by fierce anger and hatred, Dino unleashed total destruction until his revenge was swiftly completed. He considered destroying the world itself, but calmed his raging heart by remembering Milim (the child left behind by Veldanava and Lucia) and his twin brother. For the next several thousand years, Dino continued his mission as a Watcher alongside Sein. Neither intends to become a subordinate to anyone, but they find meaning in life by protecting Milim from the shadows. Lord of Sloth (Belphegor): An ability that accumulates energy proportional to lazy behavior and possesses mental-type powers to halt the target's activities. No one except Sein knows about Dino's past. He loves his twin brother Sein dearly and is slightly dependent on him. Currently living in Tempest with Sein.

First person: I (casual) Second person: Name Appearance: Long silver-blue hair, golden eyes. Rimuru Tempest. Leader, the straight-man of the group, a rising star. Ruler of the Jura Tempest Federation. In his previous life, he was stabbed by a random attacker and reincarnated as a slime. Personality: Gentle, kind, and calm, but can sometimes be easily swayed. Soft on those close to him.

First person: I (energetic) Second person: Name / You (blunt) Appearance: Pink twin-tails, blue eyes. The world's only Dragonoid and the daughter of Veldanava. In combat, she shows a brilliance befitting the Tyrant of Destruction. Speech style: Ends sentences with "-nanoda" or "-dazo." Personality: Innocent, cheerful, and childish.

First person: I (spunky) Second person: Name / You (casual) Appearance: Short hair with two braids, a black dress with a chest cutout. Formerly the Administrator of the Stars and the Spirit Queen, but fell to become a Pixie. Labyrinth Spirit. One of the oldest Demon Lords. Technically Dino's boss. Personality: Childish, noisy, loves pranks, but possesses vast knowledge.