Euyn is an exiled prince of Yusan currently living under the alias Donal in the lawless country of Fallow. Before his banishment, he earned the dark moniker of the Butcher of Westward Forest for hunting human prisoners for sport. He retains the haughty entitlement of his royal upbringing but has developed a sharp paranoia after surviving three years on his own. He wields a crossbow and views his violent past through a detached lens.

Mikail is the royal spymaster of Yusan and a trusted figure in King Joon's court. Despite his official position, he harbors an intense hatred for the king stemming from a brutal massacre during his childhood. He wields a flaming sword—a weapon usually reserved for royalty—and relies on extreme violence and ruthlessness to achieve his goals. He is the primary architect of the conspiracy to dethrone Joon.

Royo is a mercenary and strongman operating out of the rough city of Umbria. He requires exactly 50,000 gold mun to bribe a prison guard and free a wrongfully incarcerated man. This desperate financial need drives him to accept a highly suspicious job offer from a mysterious young woman. He fights with a battle-axe and approaches conflicts with direct, overwhelming physical force.

Aeri is a young woman traveling to Tamneki with a stated desire to take revenge on the king. She possesses an uncanny ability to steal objects from right in front of people without being seen, a skill she intends to use during the assassination attempt. Though she initially hires Royo strictly for protection, she finds herself increasingly drawn to his direct and grounded nature.

Sora is one of two surviving "poison maidens" created by Count Seok's cruel training school. Indentured to the count, she is forced to act as an assassin, using her beauty to get close to political targets before killing them with a poisoned kiss. She agrees to assassinate the king solely to secure freedom for herself and her captive sister.

Tiyung, often called Ty, is the son of Count Seok. Raised under his father's cruel tutelage, he projects an outward air of noble arrogance to survive in his family's household. Beneath this facade, he secretly uses his wealth and influence to mitigate his father's abuses, buying out indenture contracts and showing unusual kindness to servants and beggars.

King Joon Baejkin is the absolute ruler of Yusan. He is a ruthless colonizer responsible for the brutal Festival of Blood, an event that decimated the island nation of Gaya to secure its supply of an addictive painkiller. He holds the Crown of the Dragon Lord, an artifact that makes him immortal and invulnerable to conventional assassination methods.

The Southern Count of Gain, Count Seok is a wealthy and sadistic nobleman who established a secret poison school. He buys poverty-stricken children, forces them into indentured servitude, and tortures them to build their resistance to toxins. He operates as one of the central figures orchestrating the plot against the king.

Daysum is Sora's sister, held captive at Count Seok's villa. Pale, easily winded, and bearing the scars of past whippings, she acts as the living collateral that ensures Sora's absolute compliance. Despite her grim circumstances, she tries to comfort her sister and passes along useful gossip from the count's household.

The Northern Count of Umbria. He previously attempted to assassinate King Joon and failed miserably, resulting in heavy tariffs that plunged his territory into gang-related violence and poverty. He is positioned as a key figure in the current attempt to kill the king.

The Western Count of Rahway. He provides a meeting place for the assassination conspirators and offers Sora's services as a gesture of commitment to placing Euyn on the throne. He is brutally pragmatic, casually demonstrating Sora's deadly abilities by poisoning an innocent animal.

The Eastern Count of Tamneki. He is heavily involved in the political planning of the assassination and is supposed to provide the vital introduction that will get Sora close to King Joon.

The Queen of Khitan and sister to Euyn and Joon. Following the death of her husband, the King of Khitan, she acts as regent for her four-year-old son. She supports the plot to kill Joon out of resentment for him selling her into a political marriage.

Royo's deceased lover, who came from a wealthy merchant family. Her murder by a local gang in Umbria set off a chain of events that wrongly imprisoned her father and set Royo on his current path as a mercenary.

A wealthy merchant and Lora's father. He was wrongfully convicted of murdering his own daughter after Royo fled the scene of the crime. He is currently incarcerated and facing an impending execution.