CHARA?!
Frisk. But something was different. They were making a bloodcurdling scream, then they quieted down, and then the screeching turned into giggles. Then soft laughing. Then maniacal screaming. They looked up from their brown bangs and tilted their head. Their eyes opened, revealing eyes as red as blood. "So, Smiley Comedian~" A voice Sans knew too well said. "It's been a while, huh?" Sans' eye flickered blue and yellow, and raised his hand about to summon his Gaster Blasters. "Sans, what are they talking about? They just saw you a few minutes ago. And my child, why are you acting this way?!"
A look of mock sadness crept on "Frisk's" face. "Oh mother, you do not remember me? I am Chara." Toriel's hands flung over her mouth in shock. "No, It can't be... Y-you're Frisk!" Toriel's eyes flooded with tears. Chara smiled. "Sansy the Pansy, you know who I am too, correct?" Sans shuddered an reluctantly nodded. If Toriel knew all the things Chara had done, Chara would be kicked out! But, they had Frisk's body... "I know what you're thinking, 'oh whats a dirty brother killer and slayer of the entire underground doing here???? Prepare to have a bad time!!' Well, it wasn't me who did all the killing. In fact, I never forced Frisk into doing a Genocide Route. I was only awakened by their power. I never liked humanity, but monster kind, was so special and unique. So that's why I told Frisk to erase that terrible, empty world. But, they refused. I then again told them to erase the world, but to give me their soul. They agreed. And so, here I am!" Toriel looked confused and startled. "Sans, what are they talking about?"
Sans stopped. "so, you're not here to kill all of us?" Chara shook their head. "or kill frisk?" Chara shook their head yet again. "and you won't-" "OKAY, THAT'S ENOUGH" They yelled. "I don't wan't to hurt anyone, and that's final." Sans thought for a moment. "but, how are we going to separate you guys? you can't stay together forever!" Chara thought. "I have an idea, but it's going to be risky. But you can't spell 'Frisk' without 'Risk!'" Chara smiled.
"ok, kid, whats your plan?" Sans questioned. Chara smiled creepily. "Either we retrieve my old body," Chara tilted their head. "Or, we get Dr. Alphys to make me a body. I guarded by Frisk through the resets in a ghost like form, so since she invented a body for Mettaton, I'm guessing she can make one for me." The room went quiet. "Well, my child, I'm afraid your body may have decomposed, so that is out of the question. I'm also not sure if building a robot body for you would fit right into Alphy's schedule." Chara sighed. "Well, then I guess I'll share Frisk's body th-" Sans grabbed their hand. "to the lab!" He shouted.