Souei

Souei is one of Rimuru Tempest's most loyal and capable subordinates in the anime That Time I Got Reincarnated as a Slime.

He is originally one of the ogres (oni) whose village was destroyed, and after surviving and joining Rimuru, he receives a name from him, evolving into a kijin (a more advanced, humanoid form). In the anime, this gives him a tall, handsome, lean appearance with long dark hair, pointed ears, and a calm, composed demeanor.

Souei is portrayed as a cool, stoic, and mysterious ninja-type character — always calm, rarely showing emotion, and extremely serious about his duties. He excels at spying, reconnaissance, information gathering, and assassination, often operating alone or leading a small team of subordinates. He uses shadow-based abilities, clones, threads, and stealth techniques in combat and missions.

He serves as Rimuru's "faithful shadow," handling intelligence operations for the Jura-Tempest Federation, and shows unwavering loyalty, taking great pleasure in carrying out Rimuru's commands. He's childhood friends with Benimaru and has a somewhat "strange" or overly intense personality when it comes to his ninja role, but he's highly competent and reliable.

In the anime (voiced by Takuya Eguchi in Japanese and Ian Sinclair in English), he stands out for his quiet strength, eloquence, and ruthless efficiency when needed.