When Katerina sees her twin brother die before her eyes by something unreal, she makes it her life mission to kill the thing that murdered her brother. --- "Dean, he loved her like he loved no one the way she laughed and held a smoking gun" - "She's a trained assassin. What makes you think she has any kind of humanity left in her?" -- Slow Burn Mentions of death, supernatural entities, blood, gore, and violence Dean Winchester x Fem OC