Sybil had her sights set on Bonnie Bennet on The Vampire Diaries after seeing how much she means to Enzo. In "You Decided That I Was Worth Saving," Sybil was desperate to find a way to convince Enzo to turn off his humanity and join them. But, no matter what Sybil did or said, Enzo was still fighting. After a few failed attempts at breaking Enzo, he finally did as she asked and turned off his humanity in exchange for Bonnie's life. Of course, Sybil had no intention of keeping her word: she ordered Damon to kill Bonnie as soon as Enzo flipped the switch. Damon almost killed Bonnie on The Vampire Diaries, but luckily Alaric, Stefan, and Caroline stopped him before he could rip her heart out.
Sybil did everything she could to get Enzo under her thumb, including forcing him and Damon to fight to the death unless Bonnie chose a survivor. One would live, the other would die and spend eternity in hell. At the last second, Bonnie chose to save Enzo over Damon, but Sybil decided that Damon was more loyal to her. Bonnie chose wrong, and now she had to die. In the end, Enzo turned off his humanity in an effort to save his one true love, but it didn't matter anyways. Bonnie was a threat, and, with both Enzo and Damon on her side, there was nobody to help her.
Luckily, Alaric arrived just in time with a tuning fork he found in the cave. The fork lets out a high pitched frequency that can disrupt Sybil's siren song, and weakened her enough for Stefan and Caroline to stop Damon from killing Bonnie. Not only was Bonnie saved, but the gang was able to get Sybil and Enzo into their custody. Damon, however, got away.
Sybil might be caught, but she still has a powerful hold on Damon, and it seems likely that she still has some control over Enzo. Assuming Sybil is still controlling Enzo, Bonnie will have to convince him to turn his humanity back on before he can even start to fight Sybil out of his head. And that's just Enzo. From her prison, she is still controlling Damon, even making him attack (and possibly kill) Tyler Lockwood.
Bonnie is alive, Enzo has been saved, and Sybil is currently in supernatural custody. It looks like the good guys finally have the upper hand. The only question is, how long is that really going to last?
Images: Bob Mahoney/The CW; Giphy