Hi! This is my first FanFiction, I hope you like it and I would appreciate any comments regarding the improvement of my writting. Thank You!

-Disclaimer- I do not own Blue Exoecist or the characters.

Chapter 1

This world consists of three types of humans; Pure Blooded humans, half animal half human hybrids knows as Silent Bloods and half demon half human hybrids known as Dark Bloods. These can be put in two categories; Humans which are the Pure Blooded Humans and Marked which are Silent Bloods and Dark Bloods.

They are called Marked for they are given a small tattoo on the inside of their right wrist showing there breed and class. There are 4 different classes going from 4 to 1; 4 being the most common Silent Bloods and Dark Bloods, they usually don't have many abilities and aren't very threatening to humans and 1 being the lest common, having more abilities and are the most threatening to humans. Classes 1 and 2 are usually injected with a serum called Blood Blockers these keep the abilities controlled so they are less threatening. If there Breed and class are unknown then they will be marked as an X class this is extremely rare, for you can find out a Breed and class using blood samples.

They are called Silent Bloods or S Bloods for short, for the fact that they don't show any sign of animal qualities until they turn 3 years old, Neko's being the exception they can be born with their tail, ears and fangs. About 20% of the population are these S Bloods, around 1% of these are Neko's and round 42% of all S Bloods are Dog hybrids making them the most common.

They are called Dark Bloods or D Bloods because of the colour of their blood being almost black; they make up about 20% of the population. D Bloods are normally born with their demon qualities or show signs by 2 months old. Once they show these signs they are tested using blood samples to determine their breed and class for it is harder to tell what breed a D Blood is just by look at them unlike an S Blood. Most D Bloods are from low class demons making up about 65% of the D Blood population, 30% being mid class, 4.5% being high class and 0.5% being unknown.

Everyone is aware about the Marked population but most are oblivious to the miss treatment. These Marked are out casted and abused; used for anything from experiments to slavery and everything in between, but the lucky few are taken in as pets and not miss used and some manage to stay hidden.

These lucky few are taken to a prestigious school known as True Cross Academy to learn how to live with humans. They take classes separately from the humans and have there on canvas on the school ground most to the humans that attend True Cross don't know about these classes.

If you're not one of these lucky few then you will be experimented on, used for SD fighting (S Bloods fighting D Bloods while humans bet and watch), enslaved, used as a sex slave, forced to do labour or sold to companies for work or to private buyers.

Me, my name is Rin Okumura and I am one of these Marked, an X class D Blood to be exact and no I am not one those lucky few. I was sold to one of the SD fighting clubs 6 months ago and I plain to escape and try to find my twin brother Yukio. We were separated at birth; I don't know much about him except his name and that he is human. I also know the reason we were separated and I abandoned, it's because I am a D Blood and if they knew Yukio had a Marked brother they would want to experiment on him. By 'they' I mean one ones that call themselves the Knight of the true cross and work for the Vatican.

"Get up! Your turn to fight," yelled a big man hitting the bars to my cell with a metal pole.

I get up and look around my cell seeing the cracked, dirty walls and floor, a small toilet in the corner and the small, ripped and stained mattress (if it can be called that anymore) that I sleep on.

'And here we go again, I wonder who I'll be fighting today' I thought dreading the coming events 'I hate fighting'.

I put my hands side by side ready to be cuffed so I can leave my cell. They take extra precautions because they don't give the fighters Blood Blockers so we can fight with our full strength; they also put an electronic collar around us that will shock us if we step out of line.

"You're going to be fightin the big guy, 3," the man chuckle through a devilish, entertained smirk. The marked involved in the SD fights are numbered, the lower the number the fiercer they are and I am number 23. There are about 70 D Blood fighters and 100 S Blood fighters.

Thinking as I freaking out, trying not to show how scared I am 'Shit! I hear that guy is ruthless and has never lost a fight'

'You guys are the real demons, treating us like this' I followed the man silently through a series of hallways until we reached the fighting rink. I have only fought 8 other Marked, but because I am an X class they put me with the tough ones. We finally got to the door that leads to the rink.

The rink is a large circle platform with a wall of 2 inch thick graphene encased in 2 feet thick concrete around the entire rink to protect the on viewers that sit round the top. The top of the rink is cover by a transparent electrical field that will electrocute anything that touches it, using enough volts that could kill a normal human, preventing any escape. The two thick doors on opposite ends of the rink are made from a 2 cm think sheet of graphene and are electrified; giving anyone that is in the rink no chance of escape.

And if that isn't bad enough there are different things that will rise from the ground with a quick, small vibration were something will come up and a quiet beep half a second before they come up at lightning speed leaving very little time to react. For example spicks, but no, these aren't ordinary spicks they are razor sharp and will cut through skin, flesh and bone in a matter of seconds, they are also covered with a poison at causes all your pain receptors to cry out in agonising pain.

'Well this is gonna be fun' I thought sarcastically, waiting for the rink doors to open. I hear them introducing me to the crowed as the doors started opening.

"Fuck!" this guy is huge, he is gonna kill me, all I wanted to do is turn tail and run for my life and yes I actually have a tail.

As I walk up to the starting place I analyse just how big he really is, he looked to be at least 6' tall and covered in muscles. Two curled horns that darkened at the tips to almost black, sat at the top of his head; at the end of his hands he had long sharp, claw like nails. 'This guy looks more demon then human, how am I meant to fight this guy 'looking for any kind of weak spot.