This is my first × reader so sorry if it's cringy. For those of you who don't know how this works.
(Y/N) = your name
(F/C) = favorite color
(L/N) = last name
(F/N) = full name
(F/F) = favorite flavor/food
(F/A) = favorite animal
(F/S) = favorite song
(H/C) = hair color
(E/C) = eye color
(SF/C) = second favorite color
(S/C) = skin color

(Your POV)
My name is (F/N). Aka the Black Assassin or Shadow. If you couldn't tell I'm an assassin, a professional at that. There's never been a job I couldn't complete, and I only take jobs that interest me. I'm unique, some say I'm not even human. Pfft, if only they knew how right they were. I had a very ruff past but found myself on the path of an assassin. Sure I'm young, only around 15 or 16, I don't really keep track of age.

I watched from outside the window of an old school campus that was inhabited by class 3-E. Everyone in the room was tense, I knew they were hiding guns. I saw their planning earlier. I yawned, When's that octopus getting here? I thought. *Boom!* Welp that answers my question.

He came into the classroom and set the roll book down. "Alright class let's get started shall we?" He asked.
                   ~A few minutes later~
I looked, mouth agape. A SUICIDE BOMBER! ARE YOU SERIOUS!? Okay I'm more than mad right now. Is that really the best they can come up with! And sacrificing a classmate no less! Wait hold on, HE'S ALIVE THANK GOD! Oh, oh no the octopus is p*ssed. After threatening the three who put, Nagisa was it? Up to it, things cooled down. I had to admit that kid had skills. He remained calm throughout the whole thing and didn't slip up once. I'll make sure to watch him carefully. After class was dismissed I stayed there for a while. Today was eventful and that octopus's powers were all they were cracked up to be. I climbed onto the roof of the building and took out a chocolate bar. (If you don't like chocolate change it to your favorite candy.)

Before I knew it the octopus was right next to me, appearing to be drooling. I jumped up, "HOLY S*IT!" I yelled almost falling off the roof. He caught me before I fell. I struggled, refusing to be detained. "Feisty one aren't you? Nufufufuf~." He said laughing at the end. I turned into a shadow and appeared behind him my (F/C) Dragonsteel knife at the ready. He mach twented away then appeared at my side. He jerked my hood off revealing my (H/C) hair, (E/C) eyes, and (S/C) skin. He seemed to squint at me before I got into a battle stance. "Calm down I'm not going to hurt you." He said in a relaxing tone. I didn't relax or let any weakness show. My face was a blank slate. He sighed, "Care to explain why you're here?" He asked. "My reasons for being here are none of your concern." I growled. "It is if you're outside my classroom." He said. "No it's not, an assassin's business is her own and no weird yellow octopus can tell me other whys." I responded getting annoyed. "An assassin huh? Does that mean you're here to kill me? Good luck with that." He said his face now yellow with green stripes. "No I'm not." I responded. I was about to take off, this guy is really annoying. I took one step back, two. I turned into a shadow and bolted for the forest. He seemed to be laughing but didn't follow me.

I stood against a tree panting. Shadow mode takes alot of energy. How did he sneak up on me? No one has ever done that except one person. And he disappeared without a trace. I sighed, I'm tired. I need to relax, I'm really tense. I might break something if I'm too tense. I spotted a cliff and decided that would be a good spot to chill. I walked over and sat down, my legs dangling over the edge. The size of the drop caused my heart to skip a beat. But it was relaxing. The view was amazing and a nice breeze whipped through. My (H/C) hair blew behind me, it felt nice. My senses were as sharp as ever and my hand hovered over my knife. Even if I'm relaxing I need to stay sharp. Assassin's Rule number 3: Always be alert. I heard something snap behind me. "Who's there? Don't bother hiding I know you're there." I said. "Alright, alright no need to be hostile." A male voice responded. I heard rustling then foot steps. "So who are you?" He asked. "That is none of your concern, what is it with people and being nosy?" I said mostly to myself. "Well you're interesting." He said. I didn't respond. I heard more foot steps. "Don't come any closer...please." I added. The foot steps ceased. "So can I have your name?" "..." "Not much of a talker huh?" He said. "Not usually." I responded. He had gotten closer, I sensed strong bloodlust. "Why do you insist on getting closer?" I asked. "Because it annoys you." He responded. I snickered. "So why are you here? Surely not for the scenery." I asked. "I'm going to be joining this class in a few days, thought I'd scout the place out." He explained. I shrugged, "Getting your barrings, good choice. It might help you in the long run." I commented. "So why are you here?" He asked. 

I shrugged, "I'm just here, you could say I'm here to scout as well." I said. "Maybe I'll see you around then, but who really knows?" He said. "Shadow." I mumbled. "What was that?" He asked. "That's what I go by, Shadow." I responded. With that I entered shadow mode and fled.                   ~Third person POV~                                                                                                    Little did you know that boy was going to turn your life upside down. And a whole adventure awaited you. You are (Y/N) (L/N), the Black Assassin aka Shadow. You're very skilled and very distant. You drew a line between yourself and humanity. But that line was about to be crossed over and over. This is a story between you and Karma Akabane. Be prepared, and let your journey begin.