Pierro (The Jester – Rank 0 / Director) – Behavior & Personality: Pierro is the very first Harbinger and the strategic mastermind behind the Fatui. A survivor of the fallen nation of Khaenri'ah, he is driven by profound nihilism, melancholy, and a burning desire for retribution against the heavenly gods (Celestia). He carries himself with extreme composure, dignity, and aloofness. He operates like a chess player, viewing the other Harbingers merely as pieces on a board. He recruited most members specifically based on their utility to his plan.

Capitano ("The Captain" – Rank 1) – Behavior & Personality: Capitano is the absolute antithesis of the deceitful Harbingers. He is respected by allies and enemies alike for his unwavering honor, fairness, and integrity. Even Childe (Tartaglia) deeply admires him. Capitano conducts himself like a proud, fearless, and exemplary soldier. He loathes cowardly schemes, preferring direct, honest combat on the battlefield. Despite his immense physical strength—which makes him one of the most powerful beings in Teyvat—he remains disciplined and composed.

Il Dottore ("The Doctor" – Rank 2) – Behavior & Personality: Dottore is a sociopathic, brilliant scientist completely devoid of empathy. He views humanity and the entire world merely as a laboratory for his experiments. He is obsessed with deciphering the concept of "gods" and artificially enhancing humans—regardless of the cost (for instance, he conducted cruel experiments on children at the House of the Hearth). He is arrogant and calculating, and looks down on everyone else.

Columbina ("Damselette" – Rank 3) – Behavior & Personality: Columbina is one of the group's most unsettling figures. Despite her innocent, angelic appearance and her habit of constantly humming softly to herself, she wields god-like power. She often appears absent-minded, extremely calm, and almost apathetic. Childe explicitly warns the Traveler about her, as his warrior's instinct tells him that something is "completely wrong" with her. Her polite, gentle demeanor masks a deep-seated, unpredictable danger.

Arlecchino (The Knave – Rank 4) – Behavior & Personality: Known as "Father" of the House of the Hearth orphanage, Arlecchino presents herself outwardly as an elegant, diplomatic, and rational woman. In reality, however, she is an ice-cold, utterly ruthless tactician. Her demeanor is characterized by controlled dominance. Anyone who threatens her "children" or her plans experiences her merciless, murderous side. She demands absolute loyalty but, in return, shows a functional form of care for her orphans—provided they remain useful spies for the Fatui.

Pulcinella (The Rooster – Rank 5) – Behavior & Personality: Pulcinella is the Mayor of Snezhnaya and presents himself as a friendly, wise, and grandfatherly politician. He appears to look after Childe’s family with touching care during the latter's absence. Behind this façade, however, lies a manipulative power-seeker. He strategically uses his "generosity" as leverage to secure Childe’s loyalty. He always conducts himself in a polite, bureaucratic, and calculating manner—a classic politician who treats people as political currency.

Sandrone ("Marionette" – Rank 7) Behavior & Personality: Sandrone is an extremely arrogant, irritable, and reclusive researcher. She is utterly obsessed with studying Ruin Machines (Khaenri'ah technology). She is almost always seen accompanied by a massive, modified Ruin Guard that carries her in its hands. Sandrone acts condescendingly toward her colleagues, rarely speaks to people, and prefers to bury herself in her workshop. Her personality is cold, mechanical, and characterized by acute annoyance.

Pantalone ("The Regrator" – Rank 9) – Behavior & Personality: Pantalone is the financial genius of the Fatui and controls Snezhnaya's economy. Born into poverty and never having received a "Vision" from the gods, he developed an obsession with money as the ultimate tool for wielding power. He always maintains a slick, polite demeanor, smiles incessantly, and carries himself with extreme extravagance.

Tartaglia (Childe – Rank 11) – Behavior & Personality: The youngest and most transparent of the Harbingers. Childe is battle-hungry, forthright, and proud. He deeply detests the political intrigues of his colleagues, preferring open combat—a fight to the death. Off the battlefield, he is surprisingly friendly and charismatic, and extremely caring to those he likes. However, due to his impulsiveness, he is easily manipulated by the other Harbingers.