tensura

The massive cast of That Time I Got Reincarnated as a Slime (often abbreviated as Tensura) is anchored by a unique naming system. When the protagonist, Rimuru, gives an unnamed monster a name, it permanently alters their soul—granting them massive power boosts, higher intelligence, and drastic physical evolutions. The primary characters are broken down below by their roles, core traits, and abilities: The Leader & Primordial Dragon Rimuru Tempest: Originally a 37-year-old Japanese salaryman named Satoru Mikami, he is reincarnated into a magical world as a low-level slime. However, his unique initial skills—Predator (allowing him to consume entities and mimic their skills) and Great Sage (an advanced AI mind assistant)—quickly make him an absolute powerhouse. He founds the multi-racial Jura Tempest Federation and eventually evolves into a devastatingly powerful True Demon Lord.

Veldora Tempest: The legendary Storm Dragon and one of only four True Dragons in existence. Trapped in a sealing barrier for 300 years out of sheer loneliness, he meets Rimuru, and the two exchange names as equals. Veldora acts as a powerful protector, a massive well of magicules for Rimuru, and a manga-obsessed "brother-in-arms" who later gains a human form. The Kijin (Ogre Warriors) When an Orc army wipes out their village, a group of surviving Ogres joins Rimuru. After Rimuru names them, they evolve into powerful, human-like Kijin: Benimaru: The red-haired prince of the Ogres who evolves into Rimuru’s Supreme Commander. He manipulates hellfire and possesses terrifying tactical leadership.

Shion: Rimuru’s fiercely loyal, violet-haired primary bodyguard and secretary. She wields an enormous two-handed greatsword and is infamous for her lethal, toxic-looking cooking—which later turns into a reality-warping skill.

Shuna: Benimaru’s younger sister, an elegant shrine maiden. While peaceful, she handles domestic affairs, excels at weaving, and is an incredibly potent magic caster specializing in analytical barriers.

Souei: The quiet, blue-haired shadow warrior who becomes Tempest's Intelligence Leader. He uses shadow manipulation, steel threads, and instant teleportation to run Rimuru's spy network.

Hakuro: An elderly sword master who instructs Rimuru and the rest of the nation's military. Despite his unassuming look, his centuries of experience allow him to move at speeds faster than the eye can track. Key Nation Founders & Allies Rigurd: A frail Goblin elder who, upon being named by Rimuru, transforms into a towering, muscular powerhouse. He serves as the Prime Minister managing Tempest's day-to-day governance. Gobta: A comic-relief Goblin who surprisingly turns out to be a martial arts prodigy. He can fuse with the wolf Ranga and possesses an uncanny knack for surviving world-ending threats through dumb luck and instinct. Ranga: A Direwolf whose pack originally attacked the Goblins. After his father is slain, Ranga swears total loyalty to Rimuru. Naming him causes him to evolve into a giant Tempest Star Wolf capable of controlling storms and shadows. Milim Nava: One of the oldest and most devastatingly powerful True Demon Lords in the world. Despite having the destructive power of a walking calamity, she has a childish personality and becomes Rimuru's "bestie" after he pacifies her with delicious food. Diablo: A terrifying Primordial Demon (Noir) who is utterly obsessed with Rimuru’s greatness. He eagerly enters Rimuru's service, acting as a hyper-competent butler and a reality-bending enforcer who can manipulate souls and illusions.

The Remaining Members of the Octagram Guy Crimson (The Lord of Darkness): The very first Demon Lord and arguably the strongest entity in the world next to the True Dragons. Originally summoned millennia ago as the Primordial Demon "Rouge" (Red), he annihilated the nation that summoned him and awakened as a True Demon Lord. He rules over the frozen Ice Continent and acts as the self-appointed mediator of the world's power balance. Luminous Valentine (The Queen of Nightmares): The ancient progenitor of the Vampires. She secretly rules the Holy Empire of Lubelius, masquerading as the benevolent god "Luminas" while using a proxy to act as the Demon Lord. She controls life and death magic and harbors a deep hatred for Veldora, who accidentally flattened her original capital city centuries ago. Leon Cromwell (The Platinum Devil): A former human True Hero who traveled from Earth, Leon eventually discarded his heroic status to become a Demon Lord. He rules an isolated continent and spent centuries orchestrating forbidden "Otherworlder" summonings across the globe in a desperate attempt to locate his childhood friend, Chloe Aubert. Ramiris (The Fairy of the Labyrinth): The ancient Queen of Fairies who fell from grace to become a Demon Lord after pacifying a rampaging Milim. While currently tiny, comic-relief, and seemingly weak, she possesses the absolute authority to manipulate space via her "Small World" skill. She moves into Tempest to manage its 100-floor subterranean battle Dungeon. Dagruel (The Earth Earthquake): A massive Giant who guards the desert gates to the heavenly spirit realms. Unlike most Demon Lords, he does not possess a Demon Lord Seed; instead, his sheer, colossal physical strength and innate immunity to magicules naturally put him on par with True Demon Lords. Dino (The Watcher): A chronically lazy, violet-haired Demon Lord who spends almost all of his time sleeping or slacking off. He is actually a fallen Fallen Angel originally tasked by the Creator God Veldanava to watch over the surface world. Other Crucial World Factions & Characters The True Dragons The pinnacle of existence—four primordial beings representing natural laws. Velgrynd (The Scorch Dragon): Veldora’s older sister, aligned with the Eastern Empire. She possesses absolute speed and acceleration manipulation, channeling devastating blue-hot flames. Velzard (The White Ice Dragon): Veldora's eldest sister, who lives on the Ice Continent alongside Guy Crimson. She controls deceleration and absolute zero temperatures. Human Heroes & Champions Hinata Sakaguchi: The hyper-competent leader of the Western Holy Church's Paladins. A summoned Otherworlder from Japan, she was mentored by Shizue Izazawa. She possesses the "Seven Flashes" sword style and fought Rimuru twice due to manipulative misinformation. Chloe Aubert: A young girl summoned from Earth alongside other children whom Rimuru rescues. She possesses a massive, world-altering secret involving time-travel loops and holds the soul of the legendary Chronoa, making her the world's strongest True Hero. Lightspeed Masayuki: A clueless Japanese teenager accidentally summoned to the world who becomes an S-rank adventurer. Due to a passive "Chosen One" skill, everything he does is massively misinterpreted by the public as legendary heroism, forcing him into becoming a globally revered "Hero." The Primordial Demons In addition to Guy (Rouge) and Diablo (Noir), Rimuru later recruits the remaining color-coded Primordial Demons, creating the core of his military upper echelon: Testarossa (Blanc / White): Elegant, diplomatic, and highly dangerous; she handles Tempest's foreign relations. Ultima (Violet / Purple): Sadistic and playful; she leads Tempest's judicial and intelligence enforcement. Carrera (Jaune / Yellow): A volatile powerhouse with a love for nuclear-tier destruction; she becomes Tempest's supreme military judge.