Ashley awakens in a tutorial chamber, surrounded by terrified civilians and a clone of Chaos who explains the System with a grin. She learns her skill, Assimilate, and is immediately thrown into the second phase: a survival gauntlet of floating platforms and monstrous hounds. Her first kill is a stroke of desperate ingenuity; she cuts a bridge rope, sending a hound into the void. This triggers Assimilate, and she gains her first stolen Skill Tree, the Dark Hound's "Strong Jaws." The phase is a brutal introduction to the System's logic: kill or be killed, and every death is a potential upgrade. She stumbles through, her body recovering from her coma, and meets a trio of high school students who become her temporary companions. They are her first social contact, and her amnesia and apathy create an awkward but functional dynamic. The phase culminates in a chaotic melee where she accidentally causes a man's death, proving that the System's "responsibility" for a kill is a broad and dangerous concept. She emerges with a handful of Skill Points and a grim understanding of her new reality.

In the tutorial's third and final phase, Ashley is teleported into a massive maze. She avoids social contact, hunting monsters and building her arsenal of stolen skills. Her journey culminates in a sealed Domain where she must face the Goliath of the Maze, a level 15 stone behemoth, entirely alone. The battle is a brutal, one-sided affair. She is outmatched, her attacks barely scratching the monster, and she is thrown around like a ragdoll, her health bar dropping to zero. In a moment of desperate inspiration, she uses her wings to fly for the first time, then employs a combination of hot and cold water magic to crack the Goliath's knee joint. She severs its leg, causing it to topple and crush itself under its own weight. She is left broken and unconscious, but she has won. The System broadcasts her 100% contribution to the kill, revealing her identity as a Successor to the entire universe. This solo victory against a boss designed for a party marks her as a prodigy, a monster in the making, and instantly skyrockets her fame and notoriety.

After the tutorial, Ashley claims a Spire, establishing her territory. She is forced to attend the first Planetary Council meeting, a political gathering of all Spire Lords. She hides in her booth, but a noble, Fredrick von Delfort, publicly insults her and her brother Blake, calling them spoiled brats. This triggers a flood of traumatic memories and a cold, terrifying rage. She steps out of her booth, a look of pure, apathetic fury in her eyes. Using a stolen skill, Feather Shot, she pins him down with her wing-feathers, mutating his body, and then throws him from the platform into a pit of crimson energy, killing him instantly. This brutal display of power and lack of hesitation shocks the entire council. Chaos himself appears, enraged at the insults, and threatens the entire assembly, declaring Ashley his beloved daughter. This moment shatters her social anxiety and establishes her as a force to be feared, not pitied. It also forces a painful, distant interaction with her parents and a tentative, hopeful one with her twin brother, Blake.

Ashley, seeking to understand a warning from Chaos about Unique Monsters, researches them and inadvertently triggers a karmic link. A Gate tears open reality, dragging her into the First and Last Hell of the King of Destruction, a Class E Unique Domain filled with elite monsters far above her level. She is trapped. Her twin brother, Blake, the Successor of Magic, sees her being pulled in and, without hesitation, jumps in after her. They are separated across the vast, volcanic wasteland. Ashley's fight for survival becomes a desperate, multi-day struggle. She uses a cache of stolen gunpowder to destroy a kobold fortress, triggering a True Damage reflection from her Successor skill, Chaotic Source, and slaughtering dozens of monsters in a single explosion. This act of reckless genius draws the ire of a Kobold Lord, a mini-boss, who chases her across the Domain, attracting a parade of other monsters and mini-bosses. Blake finds her at the climax of this death march, and they unleash a combined, devastating ice tempest to escape. They then team up to hunt and finally kill the Kobold Lord, a victory that proves their synergy and gives Ashley a massive boost in levels and Skill Points.