✘ 'Two Connected Souls' Undertale Sans x Reader Soulmate AU

(DISCONTINUED)
'A young girl has just been living her life normally; until she turned thirteen--the age where you can find your soulmate. That was when this young girl and their parents--found out that her eyes not only changed colour, but she also had a tattoo/soulmark.'

'For years humans have been born with the ability to find their soulmates by eye colour. The first emotion you feel when you turn thirteen is the emotion that causes your eyes to change to your soulmate's.'

'Monsters have been able to find their soulmates by a tattoo of something that represents their soulmate. Humans, however, do not have tattoos unless they are a monster's soulmate.
If this is the case, the 'soulmark' as it is referred to as, will only represent the monster soulmate and will be the single soulmark used to find the other half.
A monster can find their soulmate by either of them touching the other's soulmark without having any bandage or piece of cloth in between them.

Although rare, it is not uncommon for a monster to have a human for a soulmate--so what if Sans did?'

WARNING!: This was a basic summary, I will be adding in a bit more information!
Although this IS an 'X-Reader' fanfic, (and my first at writing one) I will be giving the reader heterochromia eyes. You will be able to choose what the colour of her right eye is--but for the sake of this story, her left eye will be green.
1st Book in a Series!

AND YESS, the reader will be female. (Sorry guys!!!) I Do Not own Undertale, it is owned by Toby Fox! I do not own 'reader,' you do. (The cover art is the soulmark.)