The Yandere Gryffindor

Harry has always had feelings for Draco, or as Harry calls him, "Senpai" Everyone makes fun of him for it, until Harry snaps and kills Pansy Parkinson, who had a huge crush on Draco. Since then, he's been killing his "rivals" and the last thing they hear before he kills them is "Don't mess with my Senpai.."