A Demon among Titans

Before

-(Y/n)'s perspective
another day another mission. Where are we off to now? 20 miles away from the wall.
"hmmm" i lay on my bed with my headphones in listening to set it off tomorrow.
(Play the song above:it's a good song)
"BRAT!! Get up!" Levi shouted across my room.
"yes you little prick" I replied, teasing the short captain. Levi was a good friend of mine, so was Hanji and Erwin.
"tch, we're leaving now so hurry up" Levi left, grumbling at the nickname I gave him a few years ago.
I followed after him, hiding my music away.
                            ~*time skip*~
-3rd PoV
The world seemed to stop in its path. (Y/n) was defenceless. Dangled over the jaws of a titan, why is this happening?
Gravity pulled at their legs as the titan dropped the soldier into their mouth like popcorn, sliding down its throat. They were just eaten by a Titan. The only thing stopping them from going down into the belly of the beast was their hands.
Their ODM smashed to bits after a fall and all swords blunt. They were defenceless and their grip was fragile.
Their horse ran away so (pronouns) was alone.
This can't be it? Can it?

-(y/n) PoV
i have no choice.
Is anyone nearby?
I can't die ether way.
What if someone sees?
I have to survive somehow.
Thoughts buzzed around my head as I dug my boots into the throat walls of this beast.
Disgusting thing.
'I can handle this' a dark voice whispered in (y/n)'s ear.
'Let me take over, please' it begged.
'No one is here, you'll have no questions'

I growled. This can't be my only option. I don't want to. I don't need to succumb to you.
'I'll just get us out of this titan and then you can be in control'

I growled louder.
"I am always in control" I hissed at the shadowy illusion of a demon before starting their transformation.

-3rd person
A black snake slithered it's way up (y/n)'s body, staining their skin to a midnight black. Their (h/c) hair growing longer and the black colour crawled along every strand like a disease. They sprouted huge black horns like tree trunks out from their skull, stabbing through the neck of the titan. It froze in its tracks as it felt the soldier grow bigger and bigger and bigger. The horns cut through the skin like a hot knife to butter, sizzling the skin as the titan shrieked in pain. They soon slammed giant monsterous feet to the floor, shredding what was left of the titan. (Y/n) lifted their head and stretched their muscles. Their eyes peeled open revealing pink fire like cat eyes replacing their previous (e/c) coloured orbs (if you watch black butler then it's Sebastian's eyes in demon form)
They let a roar out without thinking, shaking the ground and piercing any creature nearby with fear.
It sounded like the screams of 10000 tourtured souls in harmonic doom. How one would expect hell to sound like.

What the half demon was unaware of is the watchful eyes of squad Levi. All terrified to the core of what just came from this titans mouth. Terrified of the beast that scared titans themselves.

(Y/n) turned in horror.
No
No
NO!
Like air leaving a balloon (y/n) deflated, falling to their knees as the inky blackness of their skin drained and they returned to human form.

Will they ever live the same now their demon form has been revealed?

Tears welled at (y/n)'s eyes as they realised how much danger they will be in.