Alison DiLaurentis

Alison DiLaurentis is the main antagonist of the fifth season of the ABC Family television series and became an anti-hero again in the second half of season five and become a tragic character and heroine in season 6.

History
When Mona Vanderwaal is revealed to be "A", she is sent to Radley sanitarium for treatment. Here, a blonde girl in a red coat takes over the "A" game and becomes the captain of the "A" team. Throughout the third season this blonde would appear to the Liars and sneak off before being caught. It wasn't until the season three finale that they caught their first glimpse. And the person under the hood is Alison DiLaurentis. She tells the Liars that she wants to come home but can't due to "A" but after Shana Fring is revealed to be "A" she comes back. In the 100th episode, The Liars realized that "A" wasn't gone and Shana wasn't the real "A" and in the finale Mona Vanderwaal figured it out. She called Aria and revealed to her that Alison herself was "A" and that she had proof. But before she could show them the proof, a blonde in a black hoodie breaks into her home and kills her. It is later revealed that Alison was not actually "A", but instead her sister, Charllote DiLaurentis, is.

Villainous Deeds

 * Blinding Jenna Marshall and blackmailing A|Toby into taking the fall.
 * Posing as Emily to trick Paige into sending her a letter and then using it against her.
 * Using the girls' secrets against them.
 * Getting CeCe Drake kicked out of college.
 * Using the N.A.T. Club's videos to threaten her various suspects.
 * Bullying all the outsiders in Rosewood High including Mona Vanderwaal and Lucas Gottesman, Cindy and Mindy and Jenna Marshal.
 * Like any other mean girl, she lives the Paris Hilton lifestyle.
 * Cece Drake was her mentor and Cece taught her everything she knows about bullying outsiders and blackmailing them. How to be a mean girl.