-Mikasa's POV-

"Levi!" The scream escaped from my mouth as Eren quickly looked up. I saw his face grimace into a tight snarl before climbing off of me to stand in front of Levi. "What do you want?" Eren growled, looking back at me, then at Levi, "You know she is mine, right?"  "Well, we'll just have to find out," Levi twitched in annoyance, "I seriously doubt an annoying brat like you would even match up to me."  Eren threw a hook at Levi, as he swiftly dodged the attack. The brown haired boy threw a jab at Levi's face as he turned his head to his side, merely missing the punch by millimeters. "You ought to work out a bit more..." Levi smirked as he swung his foot around--into Eren's gut.  A full roundhouse kick with enough power to knock you out. "Agh!" Eren clasped the side of his ribcage, "Damn you!" Levi rolled his eyes, "Now, get out of here."  Eren cast a glare at me, his eyes lit up and his mouth turned into a creepy grin. "If I can't have her..."I saw his hand slide into his pocket and take out a knife, "I'll just have to kill her, instead!" Eren lunged at me, too scared to move--who was this boy? He wasn't the Eren I used to know, nor the brother I used to have. But, I couldn't kill him, just fend him off for a while! Maybe this was all a mistake! Was this a dream? This can't be happening!

As the blade cut though the air, I saw Levi's stone hard face reach out towards me, just enough to push me out of the way. I hit the ground with a thud, and looked back up. The white shirt he wore was stained red, while the knife viciously jutted out of his skin. Levi kept his scream in and instead grimaced and made a grunting noise as he kicked Eren back and pulled the knife back out, tossing it across the floor. It made a clanging sound as it skidded across the asphalt. Someone had to knock some sense back into Eren--and only I could do it.

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A/N: Ooh!  Yandere-Eren was introduced. Sorry for the short chapter, it might be like this for the next few chapters of this story. Action will presume in chapters to come. Comment below! (I actually have no idea how this story will go, but I'll think about it.)