"Did you get the plan?" Gaster asked. Sans and Ink nodded. Ink made a portal to Underfell, they went inside.

They saw a house. "Fell is here. Come on" Ink said. "Hey!" They turned and saw a weirdly familiar skeleton and human. The skeleton wore a black fluff hoodie, a red t-shirt, black basketball shorts with a yellow stripe on each side and rubber shoes, he had sharp teeth and a single gold tooth. The human has long H/C hair, E/C eyes, she wore short black shorts, a black hoodie that doesn't fully cover her shoulders, a red off shoulders and brown boots, she wore a flirtatious smile. Ink and Sans just stared at them, but mostly at a hot Y/N. Our Y/N is pretty, and this one is hot... Sans thought. "Stop staring at my girl, bastards" Fell the skeleton said. He whispered something to Y/N and kissed her forehead, Y/N nodded and walked towards the house and went inside. "What do you want? It better not be my girl" Fell said. Ink shook  his head. "We just need your help. Our Y/N is in grave danger, there's a 50% chance she'll die and Chara is going to destroy the AUs" Fell just roared with laughter. "Chara? Pfft, I can kill her anytime. And your Y/N? I wouldn't care, just as long mine is safe" he said as he walked pass them. Ink just stared at him. "I would help if I were you. Well, the ironic thing is I am you" Sans said. Fell stopped. He turned to Sans. "If our Y/N dies, yours will too" He earned a growl from Fell. "Fine" he turned again and went inside. A moment later, he went outside again. "Okay, ready?" Ink asked. Sans and Fell nodded. Ink made a portal to Underswap, they went inside.

As soon as they did, they saw a skeleton wearing a cyan blue scarf, gloves, battle armor thingy, boots. Asleep on his lap was a human with H/C hair tied into pigtails, E/C eyes, a dress and a vest. "Hi, Blue!" Ink whispered. Blue looked up at Ink and smiled, he waved at them. He used his blue magic to put a pillow under Y/N's head. They whispered what they said to Fell earlier. "CHARA? BUT MY CHARA IS NICE" Blue said. "Ours isn't" Sans said. "CANT WE JUST TALK TO HER?" Ink shook his head. "It's already too late" Blue nodded. He took a paper and pen, he wrote a letter to Y/N. "OKAY. IM READY" Ink made a portal to Echotale, they went inside.

They saw a Y/N wearing a leather black fluff jacket with a small Gaster blaster on each side, she wore a white turtleneck sweater, a grey skirt, wedge sneakers, her hair is tied into a low ponytail. She was leaning on the wall next to a door to their house, reading a book. When Ink was about to say anything, Y/N knocked on the door. "G, dear. Someone wants to see you." A tall skeleton wearing a grey turtleneck sweater, the same jacket like Y/N's, pants, his face has two like scars like Gaster's, he was smoking. (All Sans are taller than Y/N by 1-2 inches. G Sans is taller. That doesn't mean you're small though, maybe...5'2). Y/N closed her book and gave G Sans a peck on the cheek and went inside. They said everything to him. "Okay. Just as long this AU is safe and so is my Y/N, sure" G said, still smoking. They were kinda surprised but just shrugged. "Okay. Let's just get the hardest one, Error" Ink made a portal to the void.

They saw nothing but Error, looking at a picture. "Error!" Ink said. Error turned to Ink. "W-what--what are y-you doing--doing here?" Error said, voice glitchy. They told him everything, he glared at them. "What? No. W-why--why would I-I care? I'm a-actually glad--glad t-that she's m-making--making my j-job easier" Error said bluntly. He continued to stare at the picture. "That makes me wonder...why did you stop trying to destroy AUs?" G asked. Error flinched. "I-I made--made a p-promise..." He said softly. "WHAT KIND OF PROMISE?" Blue asked, a little curious. Error went silent. "Error, please" Ink said. A moment later, one of his memories popped up.

"Y/N! No, d-don't--don't leave me!" Error begged. Y/N lied on the bed very ill. "Error...promise...me" Y/N coughed. "Promise me...you'll stop...destroying...AUs..."
"B-but-" Y/N cupped his cheekbone. "Please...?" Error cried. "D-don't leave me--me...y-you're the only one that--that I have..." Y/N stayed quiet. "I...love...you..." Y/N whispered. Finally, she closed her eyes, leaving Error sobbing hard. "Y-Y/N! No!" He just stayed there, clasping Y/N cold hand.

The memory faded. They realized the picture Error was holding is actually a sweet cheerful Y/N. "Fine...I-I'll do--do it...f-for her..." Error said as he stood up. "AWW...ERROR!" Blue said and hugged him tight.

All Sans except Ink and Classic Sans stared at a sleeping Y/N (the original one). "Now, you did a very good job you two. You too Papyrus" Gaster said. "We're ready for war." Ill save you Y/M...no matter what. Sans and Ink said.