UltSans hesitated, his steps slowing as the weight of his own thoughts pressed down on him. His fingers twitched slightly, his chest rising and falling in uneven breaths.
Then, he sighed.
His expression softened—not from relief, not from comfort, but from sheer exhaustion. He was holding himself together, barely.
UltSans:"...I hate who I truly am... Why do I have to feel bad for all of these symbiotes?... Ugh... I have to... not be myself..."
His voice was low, strained, as if forcing the words out took more effort than it should have.
Abyss, still lingering beside him, stirred. Its tendrils curled slightly, almost thoughtfully.
Abyss:"Think of it like this. Not all pure hearts remain pure. But yours does... Even if I had to clean it, it always remained pure. Just... covered."
UltSans let out a sharp, bitter chuckle—sarcastic, hollow.
UltSans (mockingly):"Aha? Yeah, sure... I'm a pure angel, the last monster from my timeline, the best you could find... Bla, bla, bla... Whatever..."
His sockets flickered with something darker, something buried deep beneath the forced sarcasm.
UltSans:"It's kill or be killed. I'm the fucking True God of HyperDeath. I killed billions over and over... Ripped off billions of souls... And yet..."
His voice wavered for the first time.
UltSans:"...Why the fuck can't I quit that promise?..."
Abyss was silent for a moment.
Then, it spoke, its voice calm, steady.
Abyss:"That promise… is a pillar. The thing that made you hold against what Hatred was."
UltSans tensed.
Abyss:"Your soul, your personality, the promise, and most importantly—your partner in soul and existence. All of these are reasons that made you stay who you are. They made you learn to have Determination. They made you improve it, evolve it into True Determination. And because of that, you faced whatever appeared against you."
UltSans' fingers twitched slightly.
Abyss:"It also affected me, for being inside your body... And as far as I can tell... You're the only one I not only find unique, or interesting..."
Abyss hesitated, then continued.
Abyss:"...But the only one I admire."
UltSans stopped.
The words hung in the air.
There was no sarcasm in them. No mockery.
No deceit.
For a moment, UltSans didn't know what to say.
His sockets flickered with something uncertain, unsteady. Then, after a moment, he let out another sigh—soft, deep, controlled.
His breath came through his nose[1], his mouth barely parting, the sound almost subtle yet filled with something heavy.
His expression remained tired.
But not as bitter.
UltSans:"...I guess... that's true..."
His voice was quieter now.
More honest.
UltSans:"Thanks..."
And with that, he continued forward.
His expression still soft.
Still tired.
But no longer alone.
UltSans continued forward, his footsteps light but wary. The flickering glow of his flame cast shadows across the grotesque hallway, stretching across the bloodstained walls like clawed fingers.
Then, the darkness moved.
Twisted figures emerged from the void—grotesque, humanoid shapes, their forms warped beyond recognition. Their flesh rippled, pulsating, caught in an endless cycle of mutation and failure.
Some had half-formed limbs, fused together at unnatural angles.
Others were trapped mid-transformation, their bodies still shifting, twisting as if they couldn't decide what they were supposed to be.
Their eyes—if they had them—were hollow, empty, yet somehow filled with an unbearable, silent agony.
The air reeked of burning chemicals, rotting flesh, and something unnatural—something worse.
And then, they moved.
A sickening, distorted gurgling sound filled the air as the failed creatures lunged.
UltSans reacted instantly.
His right hand shot forward, instinct overriding thought—
And the flame obeyed.
It expanded violently, surging outward in a massive flamethrower-like blast.
The corridor erupted in fire.
The walls, the ceiling, the twisted things that had tried to reach for him—all were consumed.
The creatures didn't even have time to scream.
The very moment the fire touched them, their unstable, mutated bodies collapsed into ash, incinerated in an instant.
The flames roared for only a moment—
Then, just as quickly as it had expanded, the inferno withdrew, shrinking back into the small glow hovering over UltSans' palm.
Silence.
Only the faint crackle of dying embers remained.
UltSans stood there, half-stunned, gasping for air.
His chest rose and fell in shaky, uneven breaths, the adrenaline still surging through him.
His fingers trembled slightly, but he forced them still.
Abyss moved.
It slid out from his back, its inky-black form coiling beside him, its presence oddly still—almost... observing.
Then, slowly, it drifted closer, moving near his face.
UltSans' breath remained heavy, fast.
His sockets flickered as he turned his head, locking eyes with the symbiote.
For a moment, neither spoke.
They simply stared.
Then—
UltSans:"Uhm... I just... reacted... What were...?"
His voice was unsteady, hoarse.
Abyss didn't hesitate.
Abyss:"Amalgamations of test subjects. The result of a twisted genetic and symbiotic experimentation..."
UltSans' jaw tightened slightly.
Abyss:"It's what remains of them."
His fingers curled into a loose fist.
He already knew what Abyss meant.
This place wasn't just a prison.
It was a graveyard.
And whatever horrors lay ahead, he was only just beginning to see them.
UltSans hesitated, his body still as he took a deep breath, trying—forcing—himself to relax. His mind raced, but he couldn't afford to be consumed by it.
He had to move forward.
Abyss, still lingering within him, remained silent.
It had watched UltSans incinerate those malformed creatures without hesitation.
And yet, it didn't feel betrayal.
Not exactly.
Symbiotes thrived by adapting to their hosts, by understanding them. But what UltSans had done—it wasn't ruthless destruction.
It was reactionary.
It was defense, not malice.
But something about it bothered Abyss.
It wasn't the act of killing.
It was the way UltSans hesitated afterward.
As if, for just a moment, he didn't fully accept his own actions.
That contradiction—it intrigued Abyss more than anything else.
After what felt like a long while, UltSans paused.
His steps slowed, and he turned back—frowning.
The elevator was still there.
Barely behind him.
His sockets narrowed.
He had walked so far.
And yet, he hadn't moved at all.
Turning forward again, his eyes flickered toward the endless hallway ahead.
No progress. No end. No change.
Something was wrong.
A low growl rumbled in his throat, frustration boiling inside him.
He had enough of this.
With an exasperated sigh, he suddenly crossed both arms—
Then, in one swift motion, he threw them outward.
Flames erupted from both hands, spreading violently through the corridor, burning everything in sight.
UltSans:"The fuck is going on?!"
The fire swallowed the walls, the ceiling, the floor—everything.
And then—
It melted.
The hallway itself began to collapse.
The walls dripped like wax under extreme heat, their surfaces twisting, morphing—revealing something else beneath.
UltSans' eyes widened slightly.
Abyss slithered out from his back, shifting beside him as it, too, looked up.
Abyss:"You should get out of here."
UltSans' head snapped toward the elevator, ready to turn back—
Only to see it was melting too.
His expression darkened.
UltSans:"Never mind... I have to create my own exit. Get back inside. This could hurt you."
Abyss didn't argue. It simply melted back into him, vanishing into his form.
UltSans lifted his right hand, fingers tightening.
A loud, mechanical crackle echoed through the air as a large Gaster Blaster materialized before him.
A twisted dragon skull, adorned with curved, jagged horns, its hollow sockets glowing with an intense golden light.
UltSans leapt upward, landing onto the blaster's back, gripping its horns like handlebars.
The instant he took control, the blaster shot upward, its mouth glowing white-hot as it fired straight into the collapsing ceiling.
The structure buckled.
Metal, wires, and debris melted away, warping under the raw energy.
The world tore apart around him, but UltSans pushed forward, the force of the blast carrying him up, up, up—
Until—
He broke through.
The cold night air rushed against him as UltSans soared above the facility.
For the first time since entering, he saw Ravencroft Institute from above.
It was a massive structure, but now, it was nothing but a burning ruin.
Abyss emerged again, shifting beside him, watching the scene below.
UltSans lifted his left hand, palm open.
More blasters appeared.
Big, floating Gaster Blasters surrounded him, their sharp, monstrous skulls all aiming downward.
His expression hardened.
And then—
He closed his fist.
The air shook as all of the blasters—except the one he sat on—fired simultaneously.
Blinding beams of destruction rained down, piercing through the building, tearing it apart at the foundation.
The Institute collapsed in on itself, crumbling under its own weight.
And then—
It exploded.
A fiery blast erupted from the wreckage, sending a massive shockwave through the night sky. The force rippled through the air, scattering debris in all directions, sealing the fate of whatever horrors had been left inside.
UltSans slowly lowered his left hand, gripping the blaster's horn once more.
The other blasters crumbled into dust, fading into nothing.
Both he and Abyss stared down at the destruction below.
Neither spoke.
Then, without a word, the blaster beneath UltSans tilted, flying away into the night.
Abyss remained silent.
It had watched everything. Every action, every reaction.
It wasn't surprised by UltSans' destructive abilities.
But it was surprised by something else.
The hesitation.
The anger was real. The frustration, the exhaustion—all of it was real.
But there was something beneath that.
UltSans hadn't destroyed Ravencroft out of satisfaction.
He hadn't relished in it.
He did it because he had to.
But had to for what?
To erase the evidence?
To eliminate threats?
To free those that had been trapped in that nightmare?
Or—
To erase something within himself?
Abyss didn't know yet.
But one thing was certain.
UltSans wasn't just a god of destruction.
He wasn't just a killer.
And despite his own words—
His soul was not as lost as he wanted it to be.
[1] That's how both Fanon and Canon variations of UltSans sigh.
Canon detail, one of the things both variations obtained from the around 20% compatibility with Frisk, was the expression. Neutral, serious, always acting muted. What makes both variations always remain silent and with their mouth closed.