Wtf is my life?

It's for the greater good (I'll give context if you ask nicely *ww*)

A guy, at least a few years above Sofia smirked at the girl. "You ready, my little girl to have more fun?" He asked her in a dark manner Sofia looked left, then right. Then let out a soft sigh. "I don't really... is this really the right thing to do?" She asked him. But he rolled his eyes. "Look here sweetie, you can either be ready or I can take over." He said. "Now what do you choose, Sofia?" The girl looked down a little and sighed. "I-I guess I am ready... like the other few times before?" She said as she started walking. But something felt... off. Dark never showed like she had time and time again. But Pulse came.
"Hello child," She would greet with her usual warm smile. The guy's eyes lit up and he smirked. "Ah a free kill, alright, alright. Just wait for her to look away and then quickly STAB her!" He laughed. Sofia would sigh and roll her eyes a little. "He-" Then a loud shriek echoed out through the area. Pulse would turn to the sound quickly, ears raising, and her usual warm expression changed to a more worried look. She would turn back to Sofia and forced a smile. "I am so sorry. But I believe I just heard my sister scream. Just wait here, I shall return..." She would whirl around and run off to check on the source of said sound. Dark Noa would growl. "Don't let her get away!"  Sofia would run after Pulse, always remaining a few metres behind her.

Sam was awaiting her sister's arrival, a blade concealed in her coat pocket. Her entire body shook from adrenaline? Or was it knowing what she had to do next? Maybe a mix of both. But she tried to convince herself mentally that all this would pay off. It would all be alright. When Pulse arrived she hugged Sam, tight. Her body shook from worry. Sam put an arm around her to hug her back. "Are you okay?" Pulse asked frantically. Holding Sam's shoulders out before her. Sam smiled a little bit to her, a sad but unreadable smile. "Yeah... I just thought that I-" Sam's ears lifted up as she heard another set of footprints. Sam then would look down and take a hold on the handle of the blade. "I- I am so sorry sis..." She muttered. "Wha-" Sam would cut her off by stabbing her sister, in the chest. Tears fell from the soulless eyes that were Sam's as she dropped the bloodied blade on the ground. Pulse would look shocked, before falling to her knees. She choked and sputtered, and blood splashed onto the ground. "S-sister..?" She choked, looking up at Sam, tears falling down her own cheeks from the pain. "...Why?" She coughed and choked some more, blood running down her chin. Sam would swallow hard and hug herself tight. Avoiding eye contact with Pulse, who was slowly dying. "I... I am so so sorry Pulse... B-but trust me... I-its probably... Its for... It's better this way..." She would look Pulse in the eyes a final time. "Just please... relax it'll all be over soon..." Pulse's eyes began to loose their shine, as she closed them one last time before fading into nothingness. Sam's ears would lay down on the top of her head as she whispered one last sentence. "Please forgive me dear sister..."
Sofia had arrived as the murder took place and watched a feeling of guilt weighing in her stomach like a weight. But her dark partner would just grumble. "She stole our kill!" He growled. Sam would glance at Sofia, quickly wipe her face on her sleeve and disappear without a trace. "Follow that rat bastard!" Sofia would take a single step. "Miss Sofia... Please don't do this... You know who I am, I was once someone you'd consider to be a friend. You know deep down in your heart this isn't right so please... Just stop here."