Art by  Igglab

(Chester and Geoff)
After stepping through the door, Geoff walked into a dark expanse. As he trudged on, it seemed, yet again, that there was no end to it. Eventually, though, the familiar figure of Lilith. Around her, all seven of the SOULs she'd collected floated in a lazy loop. In front of her, there was a large, bloodred drawing that resembled a pentagram.
"WHAT TOOK YOU SO LONG, YOU LITTLE-" Lilith began.
She didn't get to finish before Hoodie-Chester shot out a bunch of bladed chains as well as his four tentacles! Smirking, Lilith effortlessly used her dark flames to destroy the weapons and to damage the tentacles! Hoodie-Chester yowled in pain and quickly retracted the appendages. Geoff, furious at this, pulled out his staff and was about to rush forward. Suddenly, though, dark fire erupted around the companions! Chester tried to go above the fire, but the flames seemed to follow him as he moved anywhere! Geoff tried to escape as well but got the exact same result.
"UH UH, SORRY, BOYS. CAN'T HAVE YOU INTERFERING W/ THE RITUAL~ :]!"
Geoff got a confused look as Chester kept trying to escape from the flames.
"Ritual?" Geoff asked.
Rather than explain, Lilith simply giggled and made the reverse SOULs float in front of her. She then began to speak unintelligible words as the SOULs sank down to the ground. Suddenly, the SOULs' energies began to slowly drain from the things and seemed to coalesce into something! This made Geoff and Chester pause and look on in sick fascination as something formed from the energy! Slowly, something, or someone, began to form. After a while, the SOULs' power was spent and their empty selves shattered. After the reverse SOULs were destroyed, all that was left was a strange, translucent figure that looked strangely familiar. It was bowed and unmoving.
"RISE, MY WRETCHED LOVE, RISE!" Lilith shouted.
At first, nothing happened. Then, slowly, the figure began to rise stiffly. As the figure's front side became more visible, Geoff and Chester gasped, w/ Chester having a mystified look. The figure in question was none other than the spirit of Chester's dad... He looked quite different in a scary way. His eyes were pitch black and leaking, his lips were gone and his sharp teeth and gums were exposed, his fingers were bloodred and sharp, and his shirt's smiley face reminded Geoff a lot of a Nirvana shirt... Despite these horrible things, there was no denying it. This was Chester's dad, Natas, corrupted edition. Even Thread was spellbound by this. Geoff, on the other hand, was looking on in fear mixed w/ wide-eyed hatred.
"...Daddy...?" Chester asked, feeling a mix of betrayal, yet happiness at the same time as he began to smile w/ tears in his eyes.
The specter tilted his head and laughed menacingly. Geoff couldn't help but flinch at that laugh. It sounded empty and devoid of mercy or compassion. Put simply, it sounded like a laugh Satan himself would have. Except, somehow even worse!
"HEH HEH, I'M SORRY, WHO ARE YOU AGAIN :}?" Specter Natas asked.
Geoff shuddered angrily. On one hand, Natas' harsh voice was a stark contrast to the dad-like voice the False Natas had spoken w/ back in Chester's fake reality. Speaking of whom, Chester's eyes widened and his connected mouth turned to a frown.
"Wh-What?" Chester asked faintly.
Lilith walked over to her dead husband's side and smirked.
"DIDN'T YOU HEAR HIM, YOU USELESS FUCK? YOU DON'T MEAN ANYTHING TO HIM NOW!"
At that, a shadow fell over Chester's eyes and tears began to fall. Specter Natas then turned to his former wife and checked her out.
"FUCK ME, YOU STILL LOOK HORRIBLE AFTER ALL THESE YEARS, YOU WHORE!" Specter Natas exclaimed.
Lilith giggled.
"OH, YOU NO-GOOD SON OF A BITCH! I MISSED YOUR UGLY ASS, NATY-POO~. DID YOU STAY FAITHFUL?"
Specter Natas let out another dark laugh.
"OF COURSE NOT, SLUT. I FUCKED A DUMB HUMAN BIMBO AND HAD ANOTHER USELESS KID IN THE MEANTIME~!"
"HAH! THAT'S OK, I SLEPT AROUND W/ SOME OF MY VICTIMS BEFORE I KILLED THEM!" Lilith said proudly.
"HAH HAH, I'D EXPECT NOTHING ELSE FROM MY BITCH~." Specter Natas said flirtily.
Geoff nearly gagged furiously. He hated any sort of lovey-dovey crap like this. Even the more wholesome stuff Geoff's parents did still disgusted him. As for the fury, Geoff was angry that his suspicions about this scumbag dad had been correct and then some. Not had Natas left Chester and forgotten about him, but he also gleefully ignored Chester's silent, shuddering crying. Unfortunately, Geoff couldn't exactly do anything as the wretched couple flirted w/ one another. He knew that his words would fall on deaf ears.
"...HEH HEH. WHAT DO YOU SAY WE... COMBINE OUR STRENGTH?" Specter Natas eventually said, "I CAN"T DO MUCH LIKE THIS, AND PLUS, I'D LIKE TO SEE WHAT THAT UGLY BODY CAN DO!"
Lilith made a noise that sounded suspiciously like a moan as she shuddered in delight. Geoff couldn't help but retch at this/ As for Chester, even though he still had tears flowing down his face, looked on in morbid curiosity, w/ Thread mirroring the sentiment. Slowly, Specter Natas went behind Lilith. Then, suddenly, he phased right through her chest! In response, Lilith gasped w/ a smile and then moaned in sheer bliss. Geoff felt utter disgust as he nearly vomited at the revolting display while Chester and Thread were morbidly mystified.
Dear Lord, this is like a fucked up porno! Geoff thought.
Suddenly, though, Lilith hugged her chest while laughing as Natas' spirit was absorbed into her. Geoff and Chester watched on in horrified fascination as Lilith's body began to change in a very gruesome way. Her hand and feet claws, as well as her tentacles, extended and reddened, brown pants sprouted from her legs, her cloak became a dirty, dull pink as the smiley face from Natas' shirt appeared and the bottom part shortened, Lilith's head fluff became more harsh-looking and spiky, her lips disintegrated revealing sharp teeth and gums, and, last but most certainly never least, black liquid oozed from Lilith's eyesockets and completely engulfed her eyes! Once the changes were done, Geoff and Chester stared at the thing in horror. It looked like an unholy fusion of Natas and Lilith! (Though, clearly, it was more Natas). The abomination looked over itself, clearly admiring what it saw.
"OhOhO! i GoTtA hAnD iT tO yOu, YoU cUnT! iT's BeEn A wHiLe SiNcE i'Ve HaD a FuCkInG bOdY, aNd, ShOcKiNgLy, iT iSn'T hAlF bAd!" Natas/Lilith shouted.
"AHUHU! DESPITE THE MANY CHEATING SESSIONS, MY BODY HAS ALWAYS BEEN YOURS, NATY-POO~." Lilith's voice sounded.
Geoff felt like he was going to be sick, and Chester and Thread were both in starstruck horror. Natas/Lilith (or maybe it was Nalith or maybe it was Litas?) then noticed Geoff and Chester again and began to chuckle darkly.
"DoN't ThInK i FoRgOt AbOuT yOu FuCkErS :}!"
The flames then died down around the companions. Before they could react in time, however, suddenly, Nalith's four tentacles lashed out and grabbed the two! Shocked, Geoff and Chester tried to struggle, but the tentacles were too strong! Slowly, Nalith began to pull the two apart. As a result, Geoff and Chester struggled harder. To say that the separation was EXCRUTIATING, would be the understatement of a lifetime! For both, it felt like they were being ripped apart slowly bit by bit! When Chester was halfway off, the pain became so unbearable that both Geoff and Chester couldn't help but scream in agony! Nalith drank up the torture and laughed maniacally. Eventually, though, the lovers were finally separated... Geoff felt horrible as his skin stung badly and his insides felt like they'd been flambeed! For Chester, unfortunately, the separation seemed to have strained him too much. He hung limply, his form slowly devolving into a dripping, amorphous blob.

(Geoff)
"...Chester... n...no..." Geoff croaked.
Nalith then mercilessly tossed their own son aside like trash. Chester landed w/ nothing more than a simple plop a few feet away. Geoff was similarly dropped to the dark floor. Geoff, still dazed and in pain, tried to crawl his way over to Chester's unconscious form. Nalith casually stepped in front of him.
"Uh uH! yOu WaNt To GeT tO yOuR sTuPiD bOyFrIeNd? GoTtA-"
Nalith's words were falling on deaf ears. Geoff was trying to crawl around them. Smirking and shrugging, Nalith kicked Geoff kick and sent him flying about a few feet away! Nalith giggled.
"GeT uP, lItTlE fAlLeN aNgEl~," Nalith said, voice oozing w/ false sweetness.
Geoff, incredibly weak at this point, mustered up as much strength as he could to barely stand. Geoff attempted to bring out his staff as well as other weapons, but sadly, the weapons barely managed to fizzle into existence before they all vanished w/o actually forming. As such, Geoff weakly held up his fists, knowing very well that they would do absolutely nothing. Nalith giggled, shrugged, and pulled out her new weapons, large bladed chains covered in dark flames! Geoff grimaced.
FUCK. ME. Geoff thought.
FIGHT... START...
(Song: Twisted Love) (Link: https://www.furaffinity.net/view/41346768/)
The fight could barely even be considered as such. Geoff feebly tried to hit Nalith, but the blows were like soft taps. In return, Nalith simply threw, punched, and overall, brutally beat Geoff to a pulp. Geoff was little more than a ragdoll, tossed around as such. All the while, everything hurt for Geoff. He kept on feeling pain after pain after pain. Eventually, after a while of beating after beating, Geoff finally fell unconscious as well. Nalith, chuckling darkly, simply tossed him aside as well.
"HeH hEh, ThAt WaS pReTtY pAtHetIc. UnLiKe OuR oThEr PrEy, YoU'Re nOt EvEn WoRtH tHe EfFoRt. I'd rAtHeR lEaVe YoU hErE w/ ThE kNoWlEdGe ThAt... YoU fAiLeD, aNd EvErYoNe YoU lOvE wIlL dIe~!"
Nalith then laughed a laugh that sounded like broken glass. They then left Geoff and Chester behind for dead as they floated off to commence their plans...