In Season 5, Episode 12, titled " The Devil Inside ," Katherine Pierce successfully executes her plan to cheat death by permanently hijacking Elena Gilbert's body. This episode marks a dark shift in the season, focusing on Katherine’s deception and Damon’s subsequent downward spiral. 🧛 Katherine’s Master Plan

The episode ends with Damon brutally killing Aaron Whitmore , effectively burning his bridges with "Elena." 🥳 The Party & Personal Conflicts

Caroline Forbes admits to "Elena" (Katherine) that she slept with Klaus .

Heartbroken and feeling like a monster, Damon teams up with Enzo and reverts to his villainous ways.