Bloodstain

Growing up in a depressing childhood, Mikasa never considers herself as normal. Years later, her life changed when she met Eren Jaeger. For her, it feels like the colors appeared to her world for the first time. He made her life complete.
But now, someone tries to take him away from her. As her depression gone worse, she soon became homicidal which resulted to sudden disappearance of females at school.
Will Mikasa succeed in eliminating her rivals? or Will she fail to win Eren's heart?