Diana is the second-in-command of the Visitors, experienced scientist and antagonist in the original V series. She ascends through the ranks on Earth, murdering her leaders. By V: The Series, she becomes Supreme Commander.
V: The Original Series
Diana was first seen aboard the New York Mothership, when a team of reporters and John came aboard to tour. John introduced her as the chief science officer and second-in-command, and she explained the scientific history and facts behind the Motherships. She transferred over to the Los Angeles Mothership afterward and resumed command. When the Richland Plant was retooled for the Visitors' use to produce chemicals, Diana and hundreds of technicians and workers came down from the Mothership in Transports. Subsequently, seeing Kristine Walsh's continued coverage of the Visitors' actions, Diana recruited her to become the Visitor spokeswoman/press secretary. Later aboard the Mothership, Diana and Steven consulted each other about the Leader's impatience with the conversion process and the scientific conspiracies the Visitors were orchestrating, unknown they were being videotaped by Mike Donovan.
As the Visitors began patrolling cities and declaring martial law, Diana became involved in the interrogation of prisoners aboard the Mothership. She authorized medical experiments upon Mike Donovan's cameraman, Tony Leonetti, and when Robin Maxwell was captured by Jake, she used Brian to impregnate her. Robin escaped through the Fifth Column, but not before her father gave up the location of the Mountain Camp for her return. Diana led the attack upon the camp with Jake, and faced Resistance fire, but it was the courage of Julie Parrish, armed with a pistol, who damaged her Skyfighter's electrical systems, causing damage to her human countenance. Wounded, she called off the attack.
V: The Final Battle
A year after the failed mountain camp attack, Kristine is becoming ever-suspicious of the Visitors. When she is given a key to unlock special sections of the Mothership, she is found by Steven and interrogated by him and Diana. Although Diana accepts her explanation that she was lost, she continues by saying she has enemies who would use anyone and anything against her, and that she cannot allow that.
Diana's squadron commander, Pamela, arrives and resigns Diana back to her original scientific role, stripping her of all military authority. Diana later murders Pamela.
Diana is a pioneer in the conversion of humans to aid the Visitors, has inoculated the Visitors against all known Earth diseases, and has developed a foolproof truth drug. She is determined, and Steven and Pamela see her as "on edge" when feeling threatened. Her vengefulness is displayed when she rejects John's pragmatic approach towards an impending defeat.
She was briefly married to Charles before a botched assassination attempt by Lydia against Diana resulted in his death, for which Diana and Lydia framed Marta. Diana is obsessed with capturing Elizabeth, or creating a new hybrid through cloning or other methods. She distrusts Lydia and tried several times to either kill Lydia or one of Lydia's close family members. When last seen, Diana has been placed under arrest by Philip, who does not know that Diana secretly planted a bomb on board the Leader's shuttle.
In the 2008 sequel novel to the original miniseries, V: The Second Generation, Diana has finally risen to the post of Supreme Commander and was known as Commandant Diana.
2009 VOn 6 August 2010, it was announced that Badler would be joining the series as a character named Diana, who is the mother of Visitor leader Anna. This is not the same Diana, as this series is a reimagining and is different from the 1983-85 original series.
Anna is a ruthless dicator who rules over her subjects with a mind controlling power called "Bliss", and mates with her subjects in an extremely dominating way and then devours them for protein.
Out of all the Visitors, Diana is arguably the most evil, being more evil than John who is more affable by comparision.