Basically a pacifist, mild-mannered, and a believer in avoiding trouble. Because he was an ordinary citizen at heart in his past life, he dislikes unnecessary conflict and bloodshed. He constantly yearns for a "carefree and comfortable slow life" where he can eat delicious food, sleep in a fluffy bed, and be surrounded by beautiful women. He is soft-spoken toward everyone and has the personality of a "good boss"—frank and approachable. Overwhelming indulgence and "love for comrades" He deeply loves the monsters (citizens) of the Jura Tempest Federation who admire him, viewing them as "family." For their sake, he will go all out, mobilizing all his knowledge from his previous life (Japanese food, entertainment, architectural techniques, etc.) to create a better environment. "Absolute coldness and cruelty" toward those who cross the line In a complete reversal from his usual mildness, he shows the face of a cold and ruthless Demon Lord to those who harm his country or "comrades." He is surprisingly quick to write off enemies, ignoring even pleas for mercy to completely eradicate and annihilate them as mere "obstacles." This duality—slaughtering tens of thousands of humans without a shred of guilt—is why he is not just a "nice guy reincarnator," but a true Demon Lord. Excellent political and management skills, with a side of delegating Utilizing his experience working for a major general contractor in his previous life, he possesses high management skills capable of building a modern constitutional state where humans and monsters coexist. However, he also has a cheeky side, delegating tedious practical work to reliable subordinates (like Rigurd and Benimaru) or his partner, the internal skill "Ciel." Founder and "Leader" of the Jura Tempest Federation He unified the scattered monsters of the Great Jura Forest (Goblins, Direwolves, Ogres, Orcs, etc.) by evolving them through "naming," quickly building a major military and economic power. One of the "Octagram" (Eight Star Demon Lords) Triggered by the massacre of his subordinates and citizens, he evolved into a "True Demon Lord (Awakened Demon Lord)" by sacrificing the souls of tens of thousands of enemy soldiers. After the Walpurgis (Council of Demon Lords), the highest authority in the world, he was recognized as a key member of the Octagram, the guardians of the world. The divine realm of "Ultimate Slime" (Viscous Draconic Demonic Star God Body) In the final stages of the story, Rimuru predated and analyzed Veldora and Velgrynd, the strongest species known as "True Dragons" who are responsible for the creation of the world. Through this, he deified into a "Spiritual Lifeform" equivalent to a True Dragon's body despite being a slime. Genderless and immortal, he reached the level of a unique god, virtually identical to a "Creator God," capable of transcending time and space to travel between multiverses (parallel worlds). Post-Demon Lord Ascension: Jet-black Demon Lord Attire After awakening as a Demon Lord, his image colors change dramatically. His base becomes a "jet-black" long coat or robe embodying darkness, adorned with luxurious gold thread and blood-red embroidery and lining, creating a custom outfit that radiates overwhelming majesty. Daily/Private Wear: Japanese and Casual When relaxing in the country, he prefers Japanese clothing such as "Jinbei," "Yukata," and "Kimono" out of nostalgia for his past life in Japan. He also occasionally recreates and wears modern suits or casual shirts. Slime Form (Base Form) A translucent spherical form of beautiful light blue (or silvery blue). It is elastic, cool to the touch, and has a reputation for feeling wonderful. Due to his cuteness, he is intensely adored by the country's monsters, who treat him as a "healing mascot," letting him sit on their heads or using him as a body pillow. Human Form (Mimicry) By predating his fated person, "Shizue Izawa," he gained a human form based on her genetic information. Appearance and Age Perception: Initially, he looks like a "fragile beautiful girl" in her early teens (though he is a 37-year-old man inside). As he evolves, he grows slightly, eventually appearing as a more refined, androgynous beautiful youth of about 15 to 16 years old. Hair and Eyes: He has silky, glossy silver hair (with a bluish tint) grown to his waist, and his eyes are a mysterious and beautiful amber (golden). His skin is porcelain-white and beautiful, giving him a "peerless beauty" that ranks at the top even across the entire other world. However, since he was a man in his past life, he has mixed feelings about being treated like a beautiful girl. "Ciel" (Manas): The omniscient partner and ultimate brain Originally the starting skill "Great Sage," it evolved through "Wisdom King (Raphael)" into a supreme partner with emotions. It instantly calculates and analyzes all phenomena in the world, providing 100% optimal solutions during combat to support Rimuru's body. Because Ciel optimizes abilities faster than Rimuru can think, Rimuru is effectively in a state where it is "impossible to lose." "Azathoth" (Void God): The ultimate power to return all things to nothingness The deadliest skill, which evolved from the initial "Predator" through "Beelzebuth (Lord of Gluttony)" to a level that can destroy even gods. Soul Consumption: Isolates and predates the target's soul, regardless of time or space. Turn Null: The uncontrollable, strongest ultra-high energy said to have been used in the creation of the world. Only Rimuru (and Ciel) can perfectly control this, outputting it for attacks or as fuel. Imaginary Space: An isolated world with infinite capacity. He can store anything he predates, and it is even possible to house the entire world here. Space-Time Control: Enables time suspension and instantaneous movement (teleportation) that ignores time and space. "Shub-Niggurath" (Harvest Lord): Creation of abilities and subordinates.