Ariana Braxton is the true main villainess from Lifetime's Murder on the 13th Floor.
She was played by Jordan Ladd.
Ariana is the insecure wife of Jordan Braxton, though their marriage hasn't been a happy one in some time. It gets worse when Ariana discovers that Jordan has been having an affair with their live-in nanny, Nia. After learning that she won't get much if she goes through with divorcing Jordan, Ariana decides to take matters into her own hands and attempts to eliminate Nia in a murder-for-hire plot. Her hired guns break into the house, where Nia and Cody (Ariana and Jordan's son) are in, while the couple is at a gathering. To Ariana's dismay, she discovers in a phone conversation with her henchmen that they didn't kill Nia, but her best friend.
When Cody's life is also endangered, Ariana and Jordan rush back home, where Ariana finds Cody with Nia. Nia gives Ariana a silencer that she recently used, but once they're on the rooftop together, Ariana points the gun at Nia. Ariana screamed that Nia has ruined her life and ordered one of her hitmen to kill her. She decided to point the gun at him, but it wasn't loaded. At that point, Nia grabs the hitman's gun and shoots him to save Ariana, much to Ariana's shock. However, Ariana ends up punched by Nia, who claimed that it was the only reason why she saved her. In the film's final scene, the villainous Ariana ends up arrested for her crimes against Nia.