Nightmare's Human

A Game Changer

"SeE yOU lATeR, RaINbOW AsShOLe!" Error yelled as he jumped through the portal he made for him and Nightmare. Once both of them were through, the portal closed, and Error laughed. "THaNks FoR hElPiNg oUT aGAiN NiGHtmArE."

"Of course, Error," Nightmare replied. "Anything to help a good friend of mine. Especially if it means to help keep the balance of our multiverse."

"I KnOw tHaT, BuT yOu'Ve HeLpEd mE OuT a LoT. iT's TiMe i HeLpEd yOu oUT WitH yOUr BalANce." Error motioned for Nightmare to follow him through the Anit-void. They walked over to the area where Error had souls hang from his strings.

"How exactly are you going to help me with my balance?" Nightmare asked. "How are you even aware of my balance anyway?"

"EvEN thOuGH i'M A pARt Of a GReAtEr bAlaNCe, DOesN't MEaN i'M nOT awARe Of THe OTheR baLAncES tHaT eXiSt," Error said. "As FoR hOW, yOU'lL sEe SooN eNOugH. ThiS WilL bENeFit BotH oF uS."

Nightmare watches as Error searches the strings that the souls hang. He saw Error was focused in finding something hidden with all the strings and souls. Nightmare tries to see if he could find what Error was looking for as well. He skimmed until he caught a glimpse of bright blue, brighter than the strings holding it. Nightmare felt something strange about this soul.

Error quickly spots the very soul Nightmare spotted and have his strings lower it. Once the soul was in Error's hand, Nightmare notice how different it was from every other soul that was tied up. This soul was half red and light blue, the very soul traits for determination and patience. There was a crack that zigzagged down the middle, while another that was vertically across it from the top of the blue down near the bottom of the red. The soul was also upside down, signaling that this was a monster soul. But, the most notable thing about this very soul was the black goo that leaked out of the vertical crack just a bit.

"Error, where did you get that soul?" Nightmare asked. "How is that soul going to help us? What's so special about it other than the traits and cracks? Who does it belong to?"

"tHiS sOuL bEloNgs To mY dAUghTer LuCaRiO," Error said, as he held the soul up for both of them to look at. "sHE uSE tO hELp mE KeEP thE bALaNce By fIgHTinG InK. It'S nOt mY pLAce TO tElL hER pASt, BuT sHe WaS bORn fROm A sANs AnD cHArA. tHAt ExpLaINs SoUl TrAItS. tHE cRAcKs ArE fROm tRAuMA. tHE gOo Is A sIgN oF cONsTaNt NeGatIViTy ShE lEAkS."

"So, she'll be able to give me strength," Nightmare stated. "Is that all?"

"tHEre iS a ReAsOn LuCaRiO's mY dAUghTer," Error said. "aFtER hER AU wAs dEsTRoyEd, ShE bEcAmE aN ErRoR lIKe mE. ShE CaMe To lIVe wItH mE iN tHE aNTi-vOId. tHAt'S wHEn We fOUnD oUt HeR pOwER tO cHanGE iNTo AnD uSe AnY pOwER oF aNy SaNS oR ChArA. A rEAsOn ShE hElPed mE fIghT InK aND DeStRoY AUs."

"Why haven't you brought her back?" Nightmare asked. "Why is she in SOUL form then? If she was a strong as you say she was, wouldn't she still be around?"

"sHe WaS bAdLy HuRT bY InK," Error said. "hE dUsTeD hEr, BuT nOt HeR sOUl. FaTE wIlL nOt AlLoW hEr To DiE, jUSt LikE mE." Error frowned with sadness, anger, and regret. "tHE oNlY rEaSoN FaTE alLOwS hEr To LivE iS bECauSE sHe'S mY dAUghTer. ShE kEEpS mE sAnE. GiVeS mE dRIvE tO kEEp GoINg DesPItE hOw MuCh i WaNT tO gIvE uP aND lEt ThE mULtIvERse BuRn."

"But why haven't you brought her back?" Nightmare frowned slightly. "Your daughter could've helped you with your balance as well as mine."

"I cOUlD hAvE, bUT SooN aFteR I lEArNeD InK cOuLd AcCeSs ThE AnTi-VoId," Error explains. "LuCaRiO wAsN't SaFE hERe WiTh InK bEiNG aBLe tO bUSt In HerE. BuT, nOw ThERe'S yOU."

"Me?" Nightmare tilted his head in confusion. "What about me?"

"No OnE CaN aCcEsS oR fINd yOUr AU, uNlEss YoU AlLOw It," Error says. "sHE cOUlD lIvE iN yOUr cAStLe. ThAt WaY yOU cAn GaIn PoWer, WhILe ShE's OuT oF InK's ReACh. pLuS, sHe CaN aLsO rUn MiSSiOnS fOr yOu. WhAt Do yOu SaY?"

Nightmare thinks about this arrangement. As much as he hated to admit it, Error was right. His balance was tipping to his brother's favor. Nightmare was getting weaker, and if this wasn't corrected, the AUs would grow with all the positivity and end up touching, thous causing the collapse of the multiverse. Same as if there was too much Negativity, Creation, or Destruction. The multiverse would collapse if the balance wasn't kept.

After a moment, Nightmare looked at the sou once more before meeting Error's multicolored eyes. "Well, let's see Lucario shall we?"

A/N: I'm not well versed in Undertale and their many AUs. So please forgive me if the characters are very OoC. However, my sister requested I write this for her, so how could I refuse? She even did the art for the cover.