DeathTale: Undertale AU

Asgore raised his hand, summoning a massive fireball that blazed with an intense heat. He hurled it at Frisk with all his might.

Frisk didn't flinch. They slashed through the air with their black knife, the blade effortlessly cutting through space and slicing the fireball in half.

Undeterred, Asgore summoned a barrage of fireballs, launching them in rapid succession.

Frisk remained motionless, their blade flashing with precision, disintegrating every projectile without taking a single step.

In an instant, Frisk dashed forward, appearing directly in front of Asgore. The king raised his trident in defense, but with one devastating clash, Frisk's knife shattered the trident in two.

Asgore stumbled backward, his eyes wide with shock. "Now!" he shouted.

Suddenly, a blue spear struck Frisk's chest from behind, impaling them.

Frisk turned their head slowly, their glowing red eyes meeting Undyne's determined gaze.

Standing beside her was Papyrus, his expression filled with dread but resolve.

"You devil!" Undyne shouted. "You belong in hell!"

She summoned dozens of glowing blue spears, their tips glinting with lethal energy, and launched them at Frisk in unison.

Frisk remained still, slashing through the air with a calm precision. Each spear was obliterated before it could reach them.

The spear embedded in Frisk's chest disintegrated into dust, and their wounds vanished as if they'd never existed.

Asgore, Undyne, and Papyrus watched in stunned silence.

"They... they've surpassed pain," Papyrus stammered.

Undyne struggled to comprehend what she was seeing. "How... how can this be—"

Before she could finish, Frisk vanished.

A heartbeat later, they reappeared behind Undyne.

Undyne spun around, her reflexes sharp, but Frisk was faster. With a flurry of brutal slashes, Frisk's blade tore through her repeatedly, reducing her to dust in mere moments.

Papyrus gasped in horror, unable to move as Frisk turned their glowing red eyes on him.

Papyrus tried to step back, but Frisk appeared behind him with a slash of their knife, tearing open a hole in space.

"No—no! Please!" Papyrus pleaded.

Without a word, Frisk pushed him into the void. The radiation from the tear in reality began to erase Papyrus from existence, his screams fading into nothingness.

Frisk turned back toward Asgore, their expression cold and devoid of mercy.

Asgore stood frozen, his voice trembling as he whispered, "Y-you... you monster—"

Before he could finish, Frisk's knife flashed.

Asgore's head separated from his body, falling to the ground as his form crumbled to dust.

Frisk walked toward the pedestal holding the seven human souls. With a single slash, they shattered the glass encasing them.

The souls floated toward Frisk, their light merging with the black aura surrounding them. Frisk absorbed them all, their body radiating an immense, otherworldly power.

The ground beneath them cracked and splintered as the entire Underground began to quake.

A dark aura enveloped them, their red eyes glowing brighter

Frisk stood there planning for their final move