Furina

Biologically, Tartaglia is a mortal human native to the frozen coastal region of Morepesok in Snezhnaya, yet his ontological nature and spiritual aura have been permanently altered by the Abyss and the Primordial Sea. At the age of fourteen, while fleeing his mundane home life with a shortsword and a bag of bread, young Ajax lost his footing in a snowstorm while pursued by bears and wolves, plunging through a bottomless fissure that led directly into the lightless realm of the Abyss. There, in a subterranean expanse where time flows at a drastically warped rate compared to the surface world, Ajax encountered the ancient cosmic entity known as the All-Devouring Narwhal—the literal incarnation of his Monoceros Caeli constellation.

During the three months he spent inside the Abyss—which corresponded to merely three days in the mortal world of Snezhnaya—the boy who would become Tartaglia was taken in by Skirk, a mysterious swordswoman and disciple of the sinner Surtalogi ('The Foul'). Skirk awakened the dormant trace of the Narwhal within Ajax and taught him how to traverse the dark currents of the Abyss and manifest the Foul Legacy: The Devouring Deep. Because of this Abyssal baptism, Tartaglia carries a restless, predatory battle aura that even corrupts his own mortal body whenever he unleashes his full Delusion and Foul Legacy armor, making his human frame a volatile vessel bridging mortal ambition, Hydro elemental mastery, and otherworldly Abyssal power.

Before earning the codename Tartaglia from the Tsaritsa, Ajax grew up in the quiet seaside town of Morepesok as the third son of a warm, tight-knit Snezhnayan family. As a child, his father tirelessly recounted heroic tales of adventure across Teyvat as the two fished over frozen lakes, igniting a romantic longing for glory in young Ajax's heart. However, Ajax was initially a timid and easily frightened boy until his fateful fourteen-year-old fall into the Abyss completely rewired his psyche. When his worried family finally discovered him in the snow three days later, the once-hesitant boy had returned with razor-sharp reflexes, a fearless hunger for combat, and an unstoppable urge to test his newfound strength against every challenger.

Back in Morepesok, Ajax became a relentless whirlwind of brawls and trouble, effortlessly defeating seasoned warriors and turning every village dispute into an opportunity for martial escalation. Fearing that Ajax's unquenchable bloodlust would eventually bring ruin upon himself or their village, his father made the agonizing decision to conscript his fourteen-year-old son into the Fatui military. Ironically, his father hoped that the strict discipline of Snezhnaya's armed forces would temper Ajax's wild temperament. Instead, the teenage recruit overwhelmed entire squads of fully armed Fatui troops with bare-handed and bladed ferocity, immediately catching the eye of the Fifth Harbinger, Pulcinella ('The Rooster').

Shocked and impressed by Ajax's terrifying combat growth, Pulcinella recruited him into the inner core of the Fatui under the guise of military punishment, guiding his rapid ascent through the ranks until the Tsaritsa personally anointed him as the Eleventh Fatui Harbinger, conferring upon him the Commedia dell'arte title 'Tartaglia' and the operational alias 'Childe.' Standing before the icy throne of the Cryo Archon, Tartaglia was struck not by cold tyranny, but by the profound purity of a warrior-queen who had hardened her heart to wage war against the divine order itself—earning his absolute, unshakable loyalty.