A/N: This story is completely unrelated to my other story DarknessTale and is completely non-canon as far as DarknessTale is concerned.
Frisk woke up in a bed of golden flowers. She was in the Ruins, the only area in the Underground with an opening to the surface, and she had woken up here many times before. In one of the previous timelines, she had broken the magical barrier trapping monsters underground. After living on the surface with her friends for a short time, she grew bored. She had freed the monsters without killing any of them, so this time she wanted to know what happened if she killed them all instead.
"Frisk, why have you reset the world?" Asked a familiar voice. This voice belonged to Chara, the ghost of another human girl who had fallen underground long before Frisk. "Everyone was happy. There's nothing left here for us. Why have you taken away everyone's happy ending?" Turning around, Frisk saw Chara appear.
"You'll see, Chara." Frisk replied. "I wanted to try something new."
After encountering the evil Flowey and being rescued by the kind goat monster Toriel another time, Frisk went about walking through the Ruins. Eventually, she spotted a frog-like monster known as a Froggit.
Frisk knew what she had to do, but she hesitated for a second. These monsters were once her friends. Did she really want to kill them? Then she remembered that if she did not, she would go right back to the same old boring pacifist routine and nothing would change. Frisk filled herself with Determination. She stomped on the Froggit, killing it instantly. Its body turned to dust.
"That felt…AMAZING!" She yelled, intoxicated with power.
Chara was outraged. "Frisk, why did you do that?! You know how to spare these monsters, I've seen you do it in another timeline! You've just murdered an innocent monster for no reason whatsoever!"
"That's the point, Chara. After befriending the monsters and growing bored with living with them for a while, I wanted to know what would happen if I killed them instead."
"I don't like it, Frisk. Killing monsters is wrong. But you have the power to undo your mistake. I suggest you use it and bring everyone's happy ending back. If you don't, I think you'll have a bad time."
"That's funny, Chara. Since when were you the one in control?" Frisk replied. "And the answer is no, I will not reset. I want to know what happens if I kill the monsters, and I'll find out even if I have to reset a million times."
Frisk rampaged through the Ruins, killed every monster she found and even killed her adoptive mother Toriel. She exited the Ruins and continued to hunt down and kill monsters. As she slaughtered the monsters, her Level of Violence, known as LOVE, increased exponentially and made her stronger with each kill. All of her previous friends, Papyrus, Undyne, and Mettaton died at her hands. By the end, even Flowey was terrified of her. After a long and difficult battle with Sans the skeleton, Frisk finally killed the smiley trashbag. Only Asgore, King of the Underground, remained. Though Chara had at first been disgusted at Frisk's behavior, she grew to enjoy it as much as Frisk did.
"You were right, Frisk. I haven't had this much fun in a long time. You sure showed that comedian. Now let's go kill the King."
While Frisk was fighting Sans, Flowey burrowed into Asgore's garden to warn him of the genocidal human. He appeared in the garden and found the King blissfully ignorant of the slaughter that had taken place. Had Dr. Alphys not been too consumed with grief after the death of Undyne and too busy helping monsters evacuate, she would have warned him.
"King Asgore, I'm here to warn you!" Flowey said. He was so scared, he was crying a little.
The King was startled. "What? Who said that?" He asked. He looked down and saw the flower. "Oh, there you are. What seems to be the problem?"
"There's a genocidal human killing everyone in the Underground! She's hunted down and slaughtered every monster she could find! She would have killed me too if I hadn't escaped!"
"What?! Why wasn't I warned of this sooner?!" Tell me everything!"
Flowey told Asgore about how Frisk had hunted down every monster in every area and killed Toriel, Papyrus, Undyne, Mettaton, Sans, and many other monsters. Suddenly, he heard the human's footsteps outside.
"She's here!" The flower said. "I'm too late. The human will destroy us all!" With that, Flowey disappeared into the ground.
Frisk opened the door to the throne room to find King Asgore turned around. "Curious. I've never seen a plant cry like that before." He said to himself.
Frisk was outraged. "Has the flower betrayed us?!" She thought to herself.
The King turned around and saw the teenage human girl standing in front of him. His expression turned to a mixture of fear and rage. The human's presence was absolutely terrifying, as if a cloud of pure evil had swept into the room. At the same time, however, something about her reminded him of his adopted human daughter Chara. They looked similar, but this resemblance went much deeper than mere appearances.
"So, you're the one that the flower warned me about. It took you long enough to get here."
"So, he has betrayed us." Frisk thought to herself. "There will be hell to pay."
Asgore continued. "The flower told me all about your evil deeds. You hunted down and slaughtered every monster you could find and showed no pity. You killed my beloved wife Toriel, who only wanted to protect you and care for you. You murdered Papyrus, who only wanted to be your friend and help you change your wicked ways. Not even the mighty Undyne, who defied death to protect the world from you, could stop you. You went on to destroy Mettaton in one hit, and you even killed Sans. That brave skeleton sacrificed everything to keep me safe from you."
"His interference only delayed the inevitable." Frisk said with an evil grin. "I'm going to slaughter you and take your boss monster soul as a trophy."
"You fool! I am the most powerful monster in the Underground, and I have the power of six human souls on my side. You don't stand a chance. You will fall, and the Underground will live on. For the sake of all monsters, I, King Asgore, will strike you down!"
Six canisters, each containing a different colored heart, emerged from the floor. The canisters opened, and Asgore absorbed the six souls that were inside them. There was a bright flash of light, and Asgore grew to at least twice his usual size. Instead of wielding his usual magical red trident like in the previous timelines, he dual wielded tridents that glowed with the colors of all the souls that Asgore had absorbed.
"Behold the power of six human souls. With their power, I am the mightiest being on the planet. Prepare to die, human." Asgore said.
Frisk wasn't scared. "Bring it on, monster king!"
Asgore charged at Frisk, who ran out of the way. Frisk turned around, pulled out her knife, and tried to shove it into one of Asgore's feet. The knife did no damage. Asgore kicked Frisk away. Frisk groaned, got up, and charged at Asgore again. She tried to slash away at Asgore with her knife, but he blocked her attacks with one of his tridents. The human and the monster king took turns swinging at each other, but neither could land a lethal blow. They crossed blades a few times, and while a normal human would not be able to hold back Asgore's attacks, Frisk's high levels of LOVE made her extremely strong.
Frisk was determined not only to win, but to rub her victory in Asgore's face as much as possible. "Do you know why your people are dead, Asgore? It's because you were too afraid to protect them. You act heroic, but we both know that you're nothing more than a coward. Your people died because you failed them as a king. And now you will die in an empty kingdom where no one remembers you."
Frisk's words angered Asgore. He let out a shout of fury, and pushed Frisk backwards. "I may not have made the best decisions, but now I atone for my mistakes. I will end your reign of terror, and the Underground will be built anew." Asgore launched a fireball at Frisk, who jumped out of the way.
The whole throne room was ablaze as Asgore threw a barrage of fireballs all over the place. Frisk was able to dodge most of them, but was hit by a few stray fireballs. She took a few hits to some of her limbs, and her sweater was singed. Despite this, she stayed determined and lunged at Asgore. The king of monsters just jumped out of the way.
"You can't win, human. You are strong, but the power of these souls makes me a god! I will defeat you, and my kind will live on!" His tridents flashed blue and orange, meaning that Frisk would have to move or stay still depending on the color. She managed to avoid damage thanks to her honed dodging skills and reflexes.
Frisk took a few steps back and taunted Asgore some more. "You're pathetic. I'm an ordinary human girl, yet I've accomplished more and become stronger in a couple of days than you have in a lifetime, o mighty king! Tell me, what have you accomplished by sitting on your throne, waiting for humans like me to fall down? Your own death! You never stood a chance against me."
Asgore was even angrier than before. He charged at Frisk, who slid under him. Asgore turned around and crossed blades with Frisk a few more times. In this moment, the human finally managed to land a hit on the King. She plunged her knife into his stomach, and he collapsed to the floor, bleeding.
The human took a moment to gloat in her apparent victory. "Your cowardice doomed your kingdom, Asgore. It's no wonder Toriel left you. You were never worthy to rule the monsters. Once you're dead, I will hunt down those few monsters who managed to escape to Alphys' true lab. The last thought to run through their minds will be about how you, their once-proud ruler, failed to protect them.
This drove Asgore into indescribable rage. "How dare you mention my beloved Toriel!? I'LL MAKE YOU PAY! EVEN IF I DIE, I WILL MAKE YOU PAY!" He roared. He regained his strength, stood up, and charged Frisk one more time. She blocked his trident attacks, but he unleashed one final blast of energy with the power of the six human souls and whatever life force he had left. The energy incinerated Frisk, whose body was reduced to ashes. She was dead. Asgore had won.
A red heart floated where the human's body used to be. It was Frisk's soul. Knowing that he was about to die, the king took it. He now had seven human souls. He was truly a god. As he absorbed the soul's power, all of his wounds healed as if they had never been inflicted. While all of this was happening, he realized the true power of Determination.
As the most determined being in the Underground, he now had the power to reset. He could go back to before this human's rampage. Asgore had the human's soul, and she had been completely erased from the timeline. He could go back to before everyone had died. He could destroy the barrier. He could give the monsters the freedom that they had desired for millennia. And this human would not be there to stop him.
As the King reset the timeline, he felt that he had finally made up for his cowardice and his past mistakes. He would secure justice for the monsters, and maybe, just maybe, when it was all done and monsters ruled the earth, his beloved Toriel would love him again.
The End
