~~~~~~~~~~ A few hours later.
Y/n jerked away from Ink's side, something wasn't right. Her sudden movement startled Ink beside her. They were in the Multiverse, monitoring everything after their encounter with Dancetale. Everything seemed okay... But Y/n had a sick churning in her stomach.
"What's up Y/n?" Ink questioned beside her.
"Something's wrong... I can feel it." She watched the papers dance around them, checking for anything out of place. There... There.. was a hole in the Multiverse, between Undertale and Underfell. Exactly where Underswap should be.
"Where's Underswap?" Terror crept into her voice as she looked frantically around. Behind them rested the universe. The drawing had changed.
The background was black as blue lines stretched across the page.
"He's in Underswap!"
~~~~~~~~~~~~
As quick as possible they were in Underswap. Snowdin was silent, the air was tense. It felt colder than usual, or perhaps it was just the terror coursing through Y/n. She was in the same universe as the person who terminated hers. Maybe he even knew she was there.
"He's not here, in Snowdin at least." Ink was tense, his eyes scanned the barren town. He had his brush firmly in his grasp.
"WeLl, wElL. LoOk WhO dEcIdEd To JoIn ThE pArTy!" His glitched voice and the slicing of air was the only warning they got. Even that was enough.
Both Ink and Y/n had enough time to move as the famous blue strings shot past them. The threads didn't pursue them further, instead returned to their master. A skeleton with black bones and wild crimson eyesockets. His entire form glitched rapidly.
"Error..." Ink growled lowly, staring daggers at his enemy.
"NiCe To SeE yOu AgAiN InKy! I sEe YoU bRoUgHt ThE ERROR sUrViVoR wItH yOu. I hAvE My OwN FrIeNd WiTh Me As WeLl." A familiar friend came into view. Their monster soul was blue as the threads pulled painfully at it. Poor Blueberry had been captured by the awful glitch.
"I'm sorry Ink. He had him before I could even realize." Underswap Papyrus appeared beside Ink and Y/n. He was very distressed without his brother.
"It's okay, this is my job after all." The three of them against a glitch with a cold heart. Seemed like a fair fight. "Error, this is it. No more running away, we end this now!" Ink's voice was filled with determination. Y/n's hands gripped her brush.
"HeH, wE'lL sEe AbOuT tHaT InK." Blueberry disappeared from sight, who knew where Error stashed him. Y/n's soul appeared over her chest.
The true battle began.
The first attack went to Papyrus, who summoned a gaster blaster. With a snap of his fingers, Error teleported out of its line of fire. Ink didn't give him a break. As soon as Error reappeared Ink slashed at him with red paint. Red caused significant damage. That is, if it hits. The glitch easily side stepped the attack.
"My TuRn ThEn!" He sung, his strings shooting from his fingertips. They were aimed directly for Y/n's glowing soul. She stood there in terror as the threads advanced with lightning speed. She could only move when Ink yelled her name. She barely evaded the attack, feeling the wind as they whizzed past her. Error growled under his breath.
The threads turned sharply, coming back towards Y/n. Ink recognized with horror the same attack that she had failed to dodge during training. Y/n remembered it as well, and she was ready this time.
She turned sharply, facing the oncoming attack head on. Every action went in slow motion. Y/n swiped the ground at her feet, leaving a wide green trail across the snow. The murderous threads reached out for her soul. With a single flick of her brush, she drew up a barrier of green paint.
Ink breathed a sigh of relief, she had escaped unhurt. Y/n ran over to Ink to stand beside him. They smiled at each other.
"HoW?! InK, wHy CaN't YoU jUsT UnDeRsTaNd?! ThEsE sTuPiD uNiVeRsEs CoUlD dO sErIoUs DaMaGe To tHe WhOlE mUlTiVeRsE!" Error pressed, glitching violently. Y/n could almost feel pity for him.
"Error, if you could only see. The AUs aren't doing any damage-"
"ThAt'S a LiE aNd YoU kNoW iT!" Error's sudden attack was something no one was prepared for. It was original aimed at Ink, but someone else got caught in the cross hair. Y/n was first to notice the strings as they moved faster than before.
She shoved Ink out of the way as she replaced him. Upon contact with her, the lethal blue threads wrapped around her soul. Its color drained to the immobile blue and Y/n fell to the ground. Error's smile grew wicked.
"YoU WeRe SuPpOsE tO bE TeRmInAtEd WiTh SuRfAcEtAlE, lItTlE y/N..." Y/n gasped in pain as the strings forced her to stand up. They wrapped tightly around her soul, every tiny movement made her want to scream in pain. Ink yelled her name several times, Error chuckle darkly. "Oh, InKy. DoN't YoU kNoW nOt To BrInG sOmEoNe YoU lOvE tO a FiGhT?"
"Error please let her- NO!"
With a clench of his fist, Error shattered Y/n's soul in two. Having done their deed, the threads retreated from her soul. Ink caught her as she slumped to the ground, lifeless.
"Y-Y/n please.. Please no." Ink begged, holding onto her. The damage was done, her soul was split cleanly in two over her chest, it couldn't be fixed.
Word Count: 903