Gaster stopped a moment to ascertain what he saw on both ends of the Ruins area. He hardly hid his rising interest in this timeline, as orange and blue flames burned in each eye socket. His distorted smirk and repetitive pixelation gave in an unholy aura, scaring the monsters who had yet to fall to Frisk's slaughter.
On one hand, a Fallen Angel had recovered a little of her humanity. She met with her beloved Guardian, and her flesh pulsed with the human that saved her before he RESETS. On the other, the young human who gave his all to save the Fallen. In exchange for becoming a Demon, he slowly heals up the corrupted SOUL he was lent. In there resided the one thing W.D. Aster desired the most.
Arial, or whatever horror she turned into.
A strange turn of fate, to say the least, he dedicated his life to reviving her. He pursued the abyss of magic to find his beloved, in hopes he could revive her. It seems he found something close to her as he fueled her remains through the DT machine, but the experiment went astray and revived his significant other as an avatar of vengeance.
She had already done enough for Monsterkind, and she craved revenge on humans.
Aster underestimated the parameters of the "Void" he ventured into to find his last memories of Arial.
He was for one keenly interested to know what the abyss held other than a chance to reunite his family. He also knew the deeper he ventured, the harder it would be for him to come back. He had been there more than once, and on some occasions, people either ignored him or forgot who he was. It occurred enough times to let Aster know he should not take his passages to the Void lightly.
He had not anticipated Arial would trap him there for good.
Aster observed Chara and Toriel's interactions and was touched by the proximity they still had. The good-turned-bad Frisk also made him curious, but he had to wait for the SOUL to be mostly healed to extract it. As Frisk was only a host for a short period, the damage would not be fatal to him. The boy had already mercilessly fought and killed five monsters now, smirking while tears fell profusely off his cheeks. That was perhaps the only variable that could ruin Aster's plan.
The child's mental state will be a wreck if all goes as it should be.
Chara was as baffled as her mother when they started talking, partly because it was hard to feel alive all of a sudden. She retained some of her ghost abilities as well, probably thanks to the vivid SOUL that spoke to her and only her.
"I am very happy for you Chara, you are alive and well."
Those were the only words the Fallen heard from that familiar voice, her heart pounding faster at each bit of the sentence. As Toriel was now hugging her daughter, Chara indulged in the embrace. Her happiness was tainted with guilt and confusion, but it was not important right now. The warmth of her mother enveloped her with a sense of safety, and her SOUL's pulse reassured her quite effectively.
She was certain to be alive.
"Mother"
"Yes, dear?"
"Please ... forgive me."
"What about, dear?"
"Me being a suicidal coward, taking my brother away in a foolish plan and making you shun dad away because of my actions. I can never bring anything back to norm-"
"Chara."
"Y-yes mother ?!"
"We had time to grieve both of your losses, but Asgore was foolish enough to declare war. See, I forgave you a long time ago. Rather, I felt like I already did recently. I do not know why, but I ..."
Toriel paused as she tried to remember a strange occurrence, she already met a living Chara before today, along with another human. Presently, there was only her beloved child, which made the Guardian a little anxious at the child's whereabouts.
"Mother?"
"Yes, dear?"
"Is something the matter?"
"No my child, just a strange dream. By the way, have you met another human around?"
"No mother, I saw a ghost, however."
"A human ghost?"
"A very kind and gent-" Chara blushed by herself while a smirking Toriel planned to tease her daughter a bit.
"Is that love, Chara?" The Queen was somewhat happy her daughter found bliss in her time away. She repeatedly nudged Chara, who faked a hurt look while still blushing. Time seemed to stop for a moment when the SOUL child's voice called her.
"Chara?"
"Child?"
"Name is Frisk."
"Hello, Frisk-y ... huh?" Frisky? Why is that name coming off her mouth like nothing? Chara was both embarrassed and confused, more so when the child answered as he softly giggled.
"Chara dearest, this is where we met first when I fell here."
Bliss filled the now-shining Fallen' SOUL, surprising her and Toriel. The Guardian held her hand and both saw the memory mentioned moments ago.
A younger child quietly follows Toriel through the Ruins.
"Frisk !"
Chara was about to further call the child's name, but the memory became an instant nightmare. Toriel saw herself fighting the same child, save for his oozing face and his maniacal smirk. Red orbs glowed in the dim-lighted basement, instantly closing the gap with the Queen. She readied defense magic to counter another fierce blow from the seemingly corrupt child. Yet, the next thing she knew ...
... A flash of light stroked Toriel way too fast for her to react.
Chara widens her eyes.
Why would the one human she loves strike her mother down?
Toriel was frightened, to say the least, she was not expecting to witness her death before it happens. Both mother and daughter were now on the move, now that they suspected a human was on a genocide run. Chara had to know why FRISK would go down the dark path she took many times before, she also had to protect her mother somehow.
Fifteen kills later, FRISK started to grow oddly fond of bullying monsters. It was a strange feeling to find pleasure in murder, but Chara told him about it in the previous timeline. FRISK understood he was no longer himself once he took it upon himself to restore Chara's SOUL, but he would have imagined he would thoroughly enjoy all of this.
The terrified look on their faces.
The knife carving through their hides.
The lightness of the striking blade
Their pleas of MERCY before it lands.
Their horrible squeals of agony.
It all made sense to him now.
"P. A. Y. B. A. C. K"
The word echoed through his whole being, fueling his newly acquired dark impulses. He initially fell to his knees, cried his heart out, and cursed himself for being a heartless killer. His cracked SOUL healed instantly thanks to the LOVE he acquired, but there was no way to bring back the monsters he killed. Even bullies on the surface offered some MERCY once they went overboard, but he was too strong for any monster to fight back.
One shot, one kill.
The fourth monster made him puke. The fifth almost made him faint. The sixth, seventh and eighth made him scar his arm to "punish" himself. The ninth had him hammer his head against the wall until it bled. From the tenth onwards, Frisk felt nothing else but incomprehensible pleasure. As if deep down, he always wanted to feel what is like to be the bully.
He was around nineteen kills now, when he finally encountered Napstablook. The ghost faded the moment he saw an inhuman being approaching him, fearing for his life. The mousehole still had that cheese stuck on the table, but all the checkpoint read was
"Determination."
Yes, that is all that matters right now.