OVA
Description
Souei began as one of six Ogre survivors after the Orc Lord destroyed their village. Mistaking Rimuru Tempest for a foe, he attacked but soon allied with Rimuru to defeat the Orc Lord. Following their victory, Souei and the others swore undying loyalty to Rimuru, who named them, triggering their evolution into Kijin. He mentions ancestors gifted in dark arts, suggesting a lineage suited for stealth. Within the Jura-Tempest Federation, Souei assumed leadership of intelligence operations based in Rimuru City.

As an Ogre, Souei possessed a lean, muscular build near Benimaru's height, dark bluish-gray skin, straight medium-length blue hair covering one eye, a single white forehead horn, blue eye-shadow, and visible white canines. His tight attire matched his agility-focused combat style. Evolving into a Kijin reduced his height to roughly 180 centimeters, giving him the appearance of a lean late-teens youth with a notably calm demeanor. Shuna designed his new dark blue attire for espionage—balanced fit to prevent snagging. This look persisted through later evolutions.

Souei maintains stoic composure and speaks eloquently, projecting confidence. He exhibits Chunibyo, embracing his ninja role with extreme seriousness, occasionally amusing or worrying companions. He ruthlessly prioritizes mission objectives over personal feelings, though insults toward Rimuru provoke intense reactions. His loyalty to Rimuru is absolute, and his friendship with Benimaru is strong and equal, no longer master-retainer. Souei proved highly competent, rapidly establishing an effective counter-espionage network that thwarted spies from nations like Dwargon, though purely magical espionage sometimes requires aid from specialists like Shuna or Diablo.

As Rimuru's self-proclaimed "shadow," Souei serves as the Jura-Tempest Federation's Minister of Intelligence and leads the covert operations unit Kurayami, specializing in espionage and counter-intelligence. He manages intelligence gathering, surveillance, and covert missions across the Great Jura Forest and beyond, reporting directly to Rimuru. His responsibilities grew with the federation, demanding meticulous oversight of security and information networks.

His combat and espionage skills include Shadow Striker for stealth and mobility, Thought Acceleration and Ultra Acceleration for rapid cognition, Sticky Steel Thread for binding and slicing, and Body Double for misdirection. He utilizes Apply Poison/Paralysis/Rot for incapacitation, and possesses Magic Sense, Multilayer Barrier, Spatial Travel, and Coercion. Signature techniques involve manipulating durable, razor-sharp threads for offense, defense, or reconnaissance, making him a versatile and lethal operative.

Souei is approximately Benimaru's age. He harbors a fondness for cats. Across all appearances, his core function remains intelligence management and covert operations, with no significant deviations in role or development.