your a shiganshina survivor, however you lost your sister during the attack due to a titan and she gave you a necklace before the titan ate her whole leaving you covered head to toe in her blood, the titans started to bite you and then titan bit your arm then someone saved you, your arm was still there but it was going to leave a big, deep, nasty scare the person who saved you picked you up and started to run to the boats but died from a heart attack due to the overwhelming pressure of the titans so you ran the rest of the way. You found yourself on the same boat as Eren, Mikasa and Armin but you're not friends with them you only know of they're existence but they don't know your existence. You lost your parents a few years ago before the fall of wall Maria from murders they where stabbed right Infront of your eyes and died you where so young then... Your sister protected you since she's older but got stabbed before you took the knife and killed the murder but you where kinda happy you're parents where gone since they abûsed you and you had so many scars from it.

But you manage to leave wall Maria safely

Your now training to be a cadet and and then Keith Shadis starts talking

Keith Shadis yells at everyone, including you.

Keith: "Alright! Listen up, you bunch of miserable brats! Welcome to the cadet corps! From this day forward, you will be molded into the ultimate weapon against the Titans! You won't have time to sleep, eat, or piss – so I hope you're all ready for some serious pain and suffering! Now get to the mess hall and we'll do training later!"