UltSans wandered through the darkened halls of the Institute, his skeletal form moving with an eerie calmness. He didn't know the layout, didn't recognize any of the sterile walls or flickering monitors—to him, this was nothing more than another lifeless maze.
But he wasn't about to stumble blindly.
Lifting his right hand, he opened his palm, and instantly, a small flame flickered into existence. It hovered just above his palm, casting long, shifting shadows along the cracked walls. The dim orange glow pushed back the suffocating blackness, illuminating the remnants of the bloodstained corridors and twisted remnants of security barriers.
The Institute had fallen into silence.
If anyone was left alive, they weren't making a sound.
Abyss saw the flame appear, its soft glow bleeding into the void-like subconscious where it resided. The symbiote had only just begun to process the strange power behind it—
But then, it felt it.
A sudden grip.
Something tightened around it, an unseen force constricting, crawling into its formless mass. Abyss jerked, instinctively shifting, but its movements only led it to see what was happening.
Hatred was growing.
Abyss' focus snapped to the entity before it—an amorphous, monstrous shadow, expanding, shifting. The deeper it looked, the more the darkness churned, as though the void itself was alive.
And Hate stared back.
Abyss didn't need to be told what this thing was. It felt it.
True, unfiltered malice.
Hatred in its purest form.
And then—it spoke.
Its voice was not sound. Not vibration in the air. It was a presence, a force that resonated from within Abyss itself. It didn't hear the voice—it felt it.
Hate:"...Did you like the show?"
The weight of those words pressed against Abyss like a slow, crushing force. It remained silent, but Hate did not expect an answer.
It continued.
Hate:"...I can feel the hate inside you too... You want space... But she won't allow you..."
Abyss stiffened.
It knew exactly who 'she' was.
Chara.
Hate's voice shifted, becoming heavier, deeper—almost seductive in its poison.
Hate:"It will be extremely difficult for you... Take me. Boost that existing hate. And all the 'corruption' will be gone from Sans. Chara will then allow you to help."
Abyss froze.
This was something it hadn't anticipated.
It was being offered power. A chance to be recognized. A chance to exist freely.
But should it accept?
It didn't get the chance to decide.
Before Abyss could react, Hate moved.
The mass of darkness melted, shifting into something more twisted. Bone-like tentacles erupted from Hate's shifting form, lashing onto Abyss with unnatural precision.
Abyss shuddered.
It couldn't move.
It wasn't just restrained—it was being pulled in.
Hate dissolved, its entire essence fusing into Abyss' form. The sensation was overwhelming—not just like absorbing something, but as though Abyss itself was being rewritten.
It could feel it.
The hate wasn't vanishing.
It was becoming part of it.
Then—silence.
The bone tentacles melted next, dissolving into Abyss as if they had never existed.
And yet, Abyss knew.
Hate was inside it now.
And it could feel itself changing.
The Evolution of Abyss
The moment Hate melted into Abyss, the symbiote's entire being convulsed. A violent shockwave rippled through its form, as though every particle of its existence had been ignited and was now being forcefully reconstructed.
Abyss twisted, contorted, and writhed, its inky-black mass fluctuating between solid, liquid, and something in between.
It didn't just feel like it was absorbing something.
It felt like it was being unmade.
The core of Abyss, the very foundation of what it was, cracked and shifted, as if its essence was being rewritten at the molecular level. The presence of Hate wasn't just fusing with it—it was reshaping it.
Hate wasn't a normal entity. It wasn't just an emotion, or a force. It was alive, with its own twisted rules, its own unnatural existence that defied logic.
Now, Abyss was becoming something else entirely.
Mutation Process
Abyss' form began to collapse inward, its black, fluidic body compressing, folding, and breaking apart. The sensation was agonizing, though pain wasn't something Abyss could experience in a physical sense. It was something deeper. Something it could feel in its very essence.
And then—it ruptured.
For the first time in its existence, Abyss bled.
Not blood in the human sense, but something far worse.
From the cracks in its shifting form, a thick, deep-red substance oozed out, glowing faintly in the suffocating darkness. It was as if something inside Abyss had been exposed—something that was never meant to be seen.
The red substance pulsed, spreading through Abyss like veins of molten corruption, intertwining with its existing black form.
It was changing.
Adapting.
Evolving.
Abyss' fluid-like body began to solidify in places, no longer just a mindless shifting mass but something with structure. The once-uniform black surface cracked, revealing deep veins of glowing crimson, pulsating as if alive.
Its movement became unnatural—not the slithering, flowing motion of a normal symbiote, but something glitching, flickering, unstable. At times, parts of its body seemed to lag, appearing in one place and then another, as if reality itself had trouble defining its existence.
Abyss' surface split further, its previously smooth, shifting body gaining jagged ridges, almost like fractured bone protrusions.
Then, something new emerged.
From Abyss' unstable, writhing body, several jagged tendrils erupted—but these were not like the symbiote tendrils of Venom or Carnage. These were sharper, crueler, twisting in unnatural angles, shifting erratically, almost as if alive on their own.
And at the end of some tendrils—faint, grinning red faces flickered in and out of existence.
Not real. Not whole. Just glimpses.
Like something was trying to peer out from within Abyss.
The corruption of Hate had not just merged with Abyss.
It had given Abyss a new nature.
Abyss was no longer just a symbiote.
It had become a living void—an entity of Hate-infused corruption, something neither fully organic nor entirely conceptual.
Final Appearance of Abyss (Symbiote Form, Not Bonded) Base Form:
Abyss is no longer a simple fluidic mass like traditional symbiotes. It has a semi-solid, ever-shifting form that flickers between stability and distortion. Its surface is jagged, with visible cracks of glowing red veins running through its deep, inky-black body. These cracks pulse with a faint, sinister glow, as if the corruption inside is struggling to escape.
Tendrils & Extensions:
Abyss' tendrils are longer, sharper, and more erratic than those of Venom or Carnage. They don't just whip and lash—they move unpredictably, sometimes glitching between positions as though space itself is struggling to contain them. At times, the tips of some tendrils form jagged, malformed claws, while others seem to dissolve into an unnatural, smoke-like substance.
Distorted Movement:
Abyss doesn't move normally. Its form flickers and lags, appearing in one place and then another, as if phasing in and out of existence. When it moves too fast, its entire body blurs, leaving afterimages that twitch and shake before disappearing.
Visual "Faces" in the Form:
At times, especially when agitated, faint red grinning faces appear on its body. These are not fully formed and do not act independently—but they flicker in and out, laughing silently, shifting and distorting. They are remnants of Hate's influence, a manifestation of the malice now ingrained in Abyss' being.
Unnatural Energy Presence:
Unlike other symbiotes, Abyss radiates an energy field—a presence that warps the air around it. This isn't physical heat or electricity, but a mental pressure that others can feel. When Abyss is near, there is a sense of wrongness, unease, and an overwhelming feeling of being watched.
The Final Result
Abyss is no longer just a symbiote in the traditional sense.
It has become something far more terrifying.
A fusion of corruption and hatred, twisted into an existence that shouldn't be possible.
It still carries the adaptive, parasitic nature of symbiotes, but now it is unstable, volatile, unpredictable.
It is not a creature that bonds.
It is a force that consumes.
And now, UltSans was walking through the dark halls of Ravencroft—unaware of the true monster growing inside him.