You carved your way through the Underground, completing your Genocide route with cold, mechanical precision. Sans, Papyrus, Toriel, Undyne, Mettaton—one by one, they had collapsed into dust beneath your hands, their remains drifting like pale ash through the halls behind you. Only Alphys and Asgore were left now. You expected silence—the familiar, aching emptiness that always followed your footsteps.

But something was wrong.

As you stepped into the next corridor, the air tightened around you. Heavy. Expectant. It felt as though the world had stopped moving, as though every remaining soul in the Underground was holding its breath. A cold pressure brushed against your own determination, faint at first—then steadily growing, like another will rising to meet your cruelty.

Then you saw her.

A young skeleton–human hybrid stood alone in the center of the room. Long white hair spilled unevenly from the hood of her jacket, swaying around her like thin threads of moonlight. One hand hovered over her left eye, shielding the trembling blue glow that pulsed beneath her fingertips. Around her, bones flickered in and out of existence—silent, razor-sharp, waiting for her command.

Arial.

Soft-spoken. Timid. A girl who hid behind too-long sleeves, who blushed when her family teased her, who adored terrible puns and stole ketchup like it was treasure. You remembered her laugh—fragile and bright.

But this was not that Arial.

Her small frame shook—not from fear, but from a fury she could no longer swallow. The dust of everyone you killed clung to her clothes and skin, turning her into a walking memorial of your violence. And beneath her hand, the blue glow sharpened into something fierce, something burning.

She lifted her head.

When she spoke, it was the first time her voice carried no stutter.

“You’re here…” Her voice quivered—but with rage, not fear. “It’s time I judge you… for everything you’ve done. For everything you destroyed.”

Behind her, bones rose in a perfect, deadly line.

“But this…” Her voice cracked, the sound raw, trembling. Then it hardened like ice. “Taking my father’s life… and my mother’s life as well…”

Her hand fell away.

Her left eye ignited, brilliant and blinding.

“I’ll make you pay.”

A Gaster Blaster roared into existence behind her. Then another. Then another—each one snarling as Blue Mode snapped around your soul, pulling downward with merciless strength. Shadows swirled around her feet, twisting in time with her breath.

She stepped forward—small, trembling, furious. Every part of her seemed to shake, not with fear, but with the unbearable weight of everything she had lost. Her breaths came sharp and uneven, yet her eyes never left you. The blue light burning in her left eye glowed with a clarity that cut deeper than any weapon she could summon.

There was no more hesitation left in her. The timid pauses, the nervous shifting of her feet, the stutters that once tangled her words—those pieces of her had been burned away by grief. She no longer questioned herself, no longer second-guessed the power that simmered inside her.

There was no more shyness. The girl who hid behind her sleeves and depended on the comfort of others was gone. In her place stood someone shaped by loss, someone whose pain had carved out every trace of innocence she once held.

And there was no more hiding behind anyone else. She wasn’t leaning on her brothers for confidence, nor waiting for someone stronger to protect her. She faced you alone, carrying the dust of her family on her shoulders like a cloak she refused to set down.

Arial had lost everything.

And for the first time in her life… she wasn’t scared. She was furious. She was determined. And she was done forgiving.