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

Thirteenth Birthday

'It's my birthday today...great...'  I mentally groaned in annoyance.  What a morning to wake up to.  I honestly HATE rain.  My parents had finally thought about going to the nearby park today, (because it's Sunday,) but no.  'It just HAD to rain today didn't it?'

I watched in anger as water droplets rolled down my window.  The once beautiful view of our garden now ruined by low clouds which made it hard to see anything outside.  Today is my thirteenth birthday...which means I get my soulmate's eye colour with the first emotion I wake up with.  But something was off.  My green left eye...was...warm.  Like a fire.  Curiosity over took my previous anger so I went to my bathroom to see why my left eye felt like this.  'Maybe looking at the mirror will tell me what's wrong with my eye.'   I forced myself to be annoyed--annoyed with my eye feeling different, annoyed with today, annoyed with my parents and the rain.  I felt the heat return.

I got all my answers from the mirror.  My left eye's iris--only my left eye's iris--was a gently glowing, deep/medium blue while my other eye stayed its usual (eye colour).  The white of my eye was black instead of what its name suggest--white.  My right eye hasn't changed at all...'is it because of my heterochromia?'  My left eye's iris looked more like a mini, small fire rather than an iris.  The colour was beautiful to look at when the background behind it was black instead of white.  My shoulder length, (hair colour) hair was messy in the mirror, but I didn't care.  Instead of brushing it I rushed out of my bathroom and went to grab my bedroom door handle when I saw 'it.'

On the back of my right hand was a deep/medium blue jacket with a white fur-lined hoodie and white accents.  A...'soulmark...'  I thought, my train of thought very slowly all of a sudden.  'My soulmate's...a...monster...?'  I finished in awe.  Monsters were only found in books and stories.  I read of how they used to co-exist with humans, but humanity banished them to the 'underground' as they call it and did so many, many years ago.  Even so, whenever someone's soulmate is a monster, they become lost or missing at some point in their lives.

Some say the monsters found them or magnetically drew their soulmate to themselves.  Others theorize that the person went to the Mt. Egott, (is that right?) which is where the monster's were banished into a hole in the ground which apparently led to the 'underground.'

I slid to the floor, my back against the unopened door, just staring at my soulmark.  I wonder if this jacket represents a jacket they own or if it's showing that my soulmate is cool and probably calm or wise, just going off the colour.  'Maybe they're funny and well-collected?  Does the jacket represent security in their life or the need for it?'

"(Name)!  Time to get up, sweetie!"  My Father's voice called to me from downstairs.  I was stuck in a daze that I just couldn't help.  The rain had caused my mind to fall into empty abyss of 'what if?' and 'maybe?'  This has been going on for minutes now.  I just helplessly stayed at my soulmark--wondering why I had to be born with this?  'Is my soulmate going to scare me when I first meet them?  Am I going to insult them or hurt their feelings accidentally?  What if they didn't want a human for a soulmate?  What if I lose my parents and my home?'  What if..?  What if...?

Doubt had filled my mind like an endless void of voices.  I snapped out of my thoughts when my dad knocked on my bedroom door: "(Name)!  It's time to get up, dear!  I've made breakfast and it's your favourite!"  My dad's voice called through the door, probably not wanting to disrespect my privacy.  "Pancakes, orange juice and chocolate!  A once a year treat you don't want to miss!"

This stopped my thoughts from swarming.  I spoke back to him through the door, standing up and brushing myself of non-existent dust, "Coming, dad!  Thank you!"