The Vampire Diaries: 10 Worst Things Bonnie Has Ever Done
2. Transfers Klaus To Tyler's Body
The Mystic Falls gang succeeds in killing Klaus Mikaelson, but the consequences include Tyler's death, as he is the hybrid's sire. While everyone is resigned to this sad turn of events, Bonnie takes matters into her own hands. She strikes a deal with the Original and agrees to transfer his spirit into Tyler's body so that her friend will live.
But she also struck the deal to save her mother, as Klaus's bloodline ran through Abby Bennett's veins. Though she had the right motivation, it still violated her friends' trust.