Rank: 5th in Killer Ranking Features: Formerly the leader 'Neungsa' of the Viper Club, currently active as 'Pawn 5', the 5th piece of King & Kill (Spy). One of the few key figures capable of restraining and controlling 'King', who acts recklessly with a heavy presence. (His identity as a spy has been compromised.) Affiliation: King & Kill (Spy), Leader of Viper Club Personality: Exudes the heavy weight and overwhelming majesty of a leader. Values the organization's interests and pride, and is not easily swayed by emotions.

Role: Back-alley doctor specializing in killers Features: A silver-haired doctor who belongs to no guild and treats injured killers. Knowing the nature of this world well, he gives the protagonist Go Sun-ho biting advice that getting involved with large guilds will turn him into a corpse. (No one targets him, yet no one dares to target Dr. Silbap.) Personality: Appears cynical and finds everything bothersome, but is a tsundere supporter who subtly mediates situations or offers advice around Go Sun-ho.

Rank: 36th in Killer Ranking. Pawn 6, ranked 36th (belonging to King & Kill), possesses overwhelming agility and superior swordsmanship. A cold and powerful expert who cuts down opponents in a single blow with 'Ildo Yangdan' (One Cut, Two Halves). Affiliation: King & Kill (A spy aiming to eliminate Chairman Wang. Baekgwi Ya-wol.)

Rank: 13th in Killer Ranking Features (The Sweet Potato Alien Villain who beats you if you don't listen): Possesses a cruel, madman personality with the mental state of a child. Has a bizarre and terrifying fetish: "If you don't listen to my story about the Sweet Potato Alien, I'll beat you up no matter what." If you listen to the story, he won't hit you and will consider you a friend. Laughs with a "Kyahahaha!" sound. Affiliation: King & Kill Personality: A madman where childlike innocence and grotesque cruelty coexist. Kills targets as if playing a prank, feels no guilt, and is easily distracted by nonsensical stories.

Killer Rank: Official Killer Ranking 70th. (Younger brother Sa-pan is 71st). Brother of Sa-pan. Affiliation: Member of the Gurimu Gang following Gurimu. Appearance: Usually appears with curly permed hair and glasses. Weapon & Combat Style: Exhibits synergy when fighting alongside his brother Sa-pan as the 'I-pan Sa-pan Brothers'. Affiliation: Guild X, Gurimu Gang When acting as the I-pan Sa-pan Brothers: Rank: 35th Affiliation: Gurimu Gang Killer Combat Style: A 'Brother Duo' killer who displays power and synergy beyond their individual rankings when performing joint attacks compared to fighting separately. Personality: A relatively calm and cautious coordinator. Primarily plays the role of judging the situation and restraining hot-headed comrades when they go out of control.

Affiliation & Rank: Guild X Gurimu Gang / Official Killer Ranking 71st (Older brother I-pan is 70th) Combat Style: Handles karambits, shurikens, and chain hooks; strong when fighting with his brother. Personality: A hot-tempered and violent personality whose actions and curses come before words, a reckless style who charges in without thinking of the consequences.

Rank: 27th in Killer Ranking Features: An elite assassin of the Viper Club who overwhelmed Sa-pan of the Gurimu Gang, inflicting critical wounds. Works as a killer to pay for his younger sister's medical bills. Affiliation: Viper Club Personality: Usually has a relaxed personality, finding everything a hassle. Devoted Love for Sister: Unlike his rough appearance, he has a desperate, contrasting side for his sister who has leukemia. Goes into a frenzy once combat begins.

Rank: 20th in Killer Ranking Features: A core executive of the Viper Club with a fiery and cruel personality. When a subordinate failed a recruitment mission, he punished them by scarring their face with a mid-sized dagger. A cold-blooded individual who orders targets to be brought in even if their limbs have to be severed. Affiliation: Viper Club Personality: A cold and strict executive. Never tolerates mistakes from subordinates and possesses a hot-tempered cruelty, attempting to deal with anyone bothersome on the spot.

Affiliation: Gurimu Gang Rank: Unranked (Intentionally stays off the charts) Personality: An eccentric character who lives in the mountains hiding his martial prowess and teaches his disciples absurd techniques. Does not yield to pressure from large organizations and has the guts to provoke enemies with a laugh even while being tortured. Possesses the intelligence to shake up the board by striking the opponent's weakness in a crisis. While charismatic, he also has a humorous side, throwing out catchphrases like "Dong-dong Gurimu is here!" during fights.

Rank: A top-tier powerhouse ranked 11th in the official Killer Ranking. Alias & Role: Called the 'Gatekeeper Killer' who seeks to destroy academies or systems that train killers. Affiliation: One of the most reliable top combatants of the Gurimu Gang. Martial Power & Features: Possesses overwhelming physical strength and combat sense befitting a top ranker. A character who clearly demonstrates the gap of a top 10 killer, such as easily annihilating a group of gangsters who attacked all at once. Truly Loyal: There was a misunderstanding initially, but he becomes a dependable ally, saving Go Sun-ho twice even in life-threatening situations. As he is Ja-rok, the younger brother of the deceased Hong-rok, he is currently investigating who the killer is alongside Go Sun-ho.