In her combined time as a Diva and a Knockout, Mickie has been a face and a heel on numerous occasions, but she has rarely acted as a villain. In one rare heel stint in WWE, Mickie acted as an obsessed fan of Trish Stratus , which became more and more twisted as time went by; to the point where she has kissed Trish once and tried to do so a number of times. Mickie's advances were often rebuffed, and it led to her unleashing her villainous side by attacking Trish in the ring. After winning her first WWE Women's Championship at Wrestlemania 22, Mickie walked around dressed as Trish, even going as far as stating that she is Trish Stratus. Later on, it was revealed that she may have done these same psychotic things to Beth Phoenix, but not much more would be revealed.
Mickie would work as a face for the rest of her WWE career and in TNA, where she would return in 2010. However, in 2012, Mickie turned heel in her match against Velvet Sky on February 9 in the UK, which was won by Velvet. Four months later, Mickie was on the verge of fully becoming a villainess due to jealousy of Velvet, who was chosen to appear in Montgomery Gentry's latest music video. During a #1 Contender's four way match that also included Brooke Tessmacher and Tara, Mickie snarled at Velvet in a jealous rage and targeted her. The angle between Mickie and Velvet ended when the latter left TNA.
It was in April 2013 that Mickie began her transition into a heel Knockout. After a year and a half out of the Knockouts Championship picture, Mickie became #1 Contender on April 18 and received her shot a week later against Velvet Sky. Knowing that Velvet had a bad right knee, Mickie targeted that body part throughout the match. Despite her villainous methods, Mickie lost to Velvet, and she was very upset after the match ended. Mickie vowed that she would be more vicious and heartless the next time she faced Velvet, and she would receive another opportunity on May 23. Mickie continued portraying a heel by slapping Velvet and later delivering a chopblock to her bad knee, leading to her Knockouts Championship victory.
For weeks, Mickie avoided Velvet's requests for a rematch by claiming that Velvet's not 100%. However, on June 13, Velvet showed Mickie a note from her doctor that said that she was healthy and cleared to compete. At that moment, the evil Mickie attacked Velvet by kicking her injured knee and placing her in a submission move; becoming a villainess for the first time since 2006. Weeks after she defeated Velvet in their rematch, Mickie defended her villainous actions by stating that she'll scratch and claw to climb the ladder in the Knockouts Division; which she symbolized by climbing an actual ladder placed in the middle of the ring. Mickie laughed evilly and stated that she'll go down in history as the greatest Knockouts Champion in history, and that no woman will be as great as her. Mickie went on to defeat Gail Kim as well, before beginning a feud with ODB. Mickie's run as a villainous Knockout ended when she left TNA after she lost the Knockouts Championship to ODB in September.
On November 30, 2014, Mickie competed in her first match since giving birth to her son, doing so against Tessa Blanchard at Queens of Combat's third show in Winston-Salem, North Carolina. The match began as a face vs face affair, but at the mid-point, Mickie turned into a villain and resorted to immoral methods to defeat Tessa, including pulling Tessa's hair and attempting to use one of the ropes for leverage. Mickie went on to defeat Tessa with a superkick.
As a villainess, Mickie was arrogant, self-centered, and she thought that every bad thing she did was justifiable. She was also prone to jealousy and fits of anger, which was proven in her feuds with Velvet Sky and Trish Stratus, respectively.