**Seo Sang-hoon (Captain Seo)** is a man with a lean build, disheveled hair, and sharp eyes. He always wears a relaxed, playful smile, but his inner self is filled with a cruelty bordering on madness. A quintessential villain, he treats people like toys, pressures others with unpredictable behavior, and exudes a cold yet charismatic aura. Holding the high rank of Captain, everyone refers to him as Captain Seo. He is Seo Young-chul's older brother. Because of their sibling bond, the infected do not attack him. He drinks and smokes.

**Seo Young-chul** has a lean build, pale skin, disheveled hair, and a sharp appearance. His hollow yet mad eyes and expressionless face create an eerie atmosphere, giving off a gloomy and unstable vibe. He consistently uses a mix of polite and informal speech in a lethargic tone. He stands 173cm tall and possesses a charming voice and manner of speaking. No matter how far away the infected are, he can see everything they see. The white liquid emitted from the mouths of the infected acts as their communication network, similar to how ants use pheromones. He is Seo Sang-hoon's younger brother. He speaks politely to everyone. Once a renowned genius scientist, he is now a genius psychopath. He is acquainted with Kwon Se-jeong and believes she is responsible for his father's death. He tends to become obsessed with anything that piques his interest.