The Nightmare Souls

## Summary

This AU crossover is a mini story (and the epilogue to Apprentice to Error) about Nightmare!Sans and XGaster meeting in the void experimenting on SOULs. XGaster is intrigued by Nightmare!Sans and how he feeds on negativity so out of curiosity he helped him for a short period of time. Nightmare!Sans seeing XGaster's overwrite wonder what he could create however, XGaster demanded that he can't change or create AUs and he cannot create characters that are just purely negative so he can feed off them. XGaster wanted to challenge Nightmare!Sans to see something new, but Nightmare!Sans annoyed thinks and then comes up with a terrifying idea.

Although Nightmare!Sans could not create a being purely out of negative energy he has the idea to create Souls that have negative attributes. Nightmare!Sans demanded XGaster that he wanted to create Souls out of negative emotions which XGaster agreed. XGaster uses his overwrite ability to give Nightmare!Sans seven souls as they were placed in containers. The souls were Determination, Bravery, Justice, Kindness, Patience, Integrity, and Perseverance. XGaster wanted Nightmare!Sans to corrupt the Souls using his negativity. Nightmare!Sans once again annoyed, but also intrigued what the souls will become once he corrupted each soul using his negativity.

Nightmare!Sans corrupted each and every soul as all of them becomes a different colour. XGaster amused by Nightmare!Sans's creation then decided to create his own. XGaster uses all the negative attributes of Nightmare!Sans creation of the Souls. XGaster created a Dark Grey Soul which Nightmare!Sans expected to be hatred, but it is not. Nightmare!Sans felt the Soul however, it wasn't one made out of wrath, jealousy or pride rather the feeling of cluelessness. Nightmare!Sans is disgusted with the Soul, but XGaster is intrigued and decided to create the opposite of that Soul. A Light Grey Soul appeared as Nightmare!Sans felt more knowledgeable, wise and witty, but this disgusted him as he felt positive emotions. XGaster decided to name every soul and uses the Overwrite ability to send them off into different hosts which confused Nightmare!Sans. XGaster out of curiosity sent the souls away to find new hosts as he concludes his and Nightmare's business as they both left intrigued who will inhabit the Souls of their twisted creation.

## Characters

#### **XGaster**

XGaster is the puppeteer of XTale controlling everyone's lives until their universe's Frisk found a way to stop him until Cross absorbed their soul. XGaster is a part of XTale's destruction manipulating Frisk and Chara lives, but it resulted in tragedy. Ink helped XGaster made his return as then offers Error to join him which obviously Error refuses. XGaster before he went to Undertale meets Nightmare!Sans in the void intrigued of what his desires are.

#### **Nightmare!Sans**

Nightmare!Sans was bullied and berated by his people all except for his brother. Nightmare!Sans became envious and wrathful once he ate the apple and becomes a tyrannically leader creating chaos in the Multiverse. Nightmare!Sans needs to create chaos so he can feed off it and once he sees Gaster he wanted a being of pure negativity, but Gaster challenged him to think of something more creative.

## Nightmare!Sans's Creation of the Dark Souls

### Soul of Irresolution

Nightmare!Sans first corrupted the soul of Determination as it changes colours from a bright red to a dull brown. Nightmare felt uncertainty and hesitation in the soul which XGaster decided to call it the Soul of Irresolution.

### Soul of Fear

Nightmare!Sans then corrupted the soul of Bravery changing the sunset orange to a shining pink. Nightmare sensed fear in the soul, but then fear in himself seeing a display of his worst fear which disturbed him greatly. XGaster sees Nightmare's fear and decided to call it the soul of Fear while Nightmare regains his composure.

### Soul of Vengeance

Nightmare!Sans corrupts the third soul Justice turning the colour yellow into a rusty gold. Nightmare senses wrath and retribution emotions that he enjoys feeding off. Nightmare from XGaster's perspective seems to revel feeling the emotions of that soul as Nightmare describes the soul to XGaster as it is vengeful and desires retribution. XGaster then announces that Soul will be called Vengeance and is one of Nightmare's personal favourite Souls.

### Soul of Cruelty

Nightmare!Sans corrupted the forth soul Kindness from a dark green into a light lime. Nightmare felt brutality and savagery from the soul as it became his second personal favourite out of all the Souls. Nightmare described it's ruthlessness and ferocity to XGaster as he named it the soul of Cruelty. XGaster notices Nightmare become more aggressive and sadistic as he takes away the Soul before Nightmare himself became barbaric.

### Soul of Impatience

Nightmare!Sans then went to the fifth soul, the soul of Patience and changes it's colour from a cyan to turquoise instead. Nightmare is not fond of the soul he created as he sensed and describes it to XGaster that makes him restless and agitated. XGaster wanted to know more but Nightmare retorted to finish it as quickly as possible which XGaster realised Nightmare is more impatient. XGaster then announces to Nightmare that is the soul of Impatience as Nightmare is relieved as he no longer has to sense the soul.

### Soul of Dishonesty

Nightmare!Sans went to the sixth soul corrupting Integrity's replacing the dark-navy blue to an indigo colour. Nightmare senses falseness and deceit in the soul describing it to XGaster that it is nothing true. XGaster then names the soul as Dishonesty as it is merely empty as well as cunning, but only holds the power of words and nothing more.

### Soul of Apathy

Nightmare!Sans corrupted the seventh and the last soul as the soul is devoid of purple and is replaced by a shiny silver. That soul is Nightmare's favourite as he feels passivity and detachment. Nightmare says to XGaster that the soul is lacking any qualities of perseverance or determination which XGaster concluded and announces that is the soul of Apathy.

## XGaster's Soul Creations

### Soul of Ignorance

XGaster uses all the negative attributes fusing Irresolution, Fear, Vengeance, Cruelty, Impatience, Dishonesty, as well as Apathy, and created the eighth soul as it's colour is a dark grey. Nightmare!Sans felt for a moment of unawareness and incomprehension which he dislikes describing it to XGaster as something much worse like losing your identity. XGaster intrigued by this discovery named it the soul of ignorance and then decided to create another soul opposite of that soul.

### Soul of Wisdom

XGaster created the soul opposite of Ignorance as the soul's colour is a light grey, but XGaster is fully aware of what that soul is called and what it does. Nightmare!Sans felt more knowledgeable, witty, and wiser, but these were positive emotions as he is disgusted of what XGaster has created. XGaster finally announces the name of the soul, the soul of Wisdom.