She has long blonde hair and beautiful blue eyes. She has a slim built but has enough strength to held her own in battle.
Diana grew from a famous family of Witches, the Cavendish. At one point, she grew to idolize a performer named Shiny Chariot. She managed to attend one but the event has caused an accident that took thousands of lives. Diana and her aides manage to escape and survive and she returned to continue her studies despite the trauma she witnessed.
She became a well renowned student and eventually been given the Shiny Rod, however she hasn't been able unlock any of the Words of Arcturus. She would soon took part in an arrange marriage leading to the birth of her daughter who she named after her late mother. However in the year 2025, her home was under attack by Seishin, a vicious group of shinobi who has a vendetta against Witches. Diana and her new born daughter managed to escape but her husband and her closest aides were killed causing what would be known as the Cavendish Massacre.
During 2033 during the war between Seishin and the last free Witches, Diana's consciousness has been taken over by another Diana Cavendish from LW - 004 allowing the latter to have full control over the body. This other Diana would learn that she has claimed the Shiny Rod but fully see the horrors in the Dark World where only a few hundred Witches are alive and Seishin relentlessly pursue them.
After barely escaping the Leader of the Seishin, Diana began to wonder what lead to this alternate world with her first thought being what happened to the Shiny Rod's intended user, Akko. Diana went to a devastated Japan but found Akko. This lead to Diana being capture by Akko revealing herself to be the Leader of Seishin.
To Diana's horror, Akko has correctly deduced that Diana came from another time after her men analyzed an anomaly. Akko intends to use the power of time to go back to the time of the Nine Olde Witches and murder them in order to prevent the future they are currently in.
In her cell, Diana finally remembered how the world came to be. She went into the past to sabotage Akko, jealous that she was given the Shiny Rod. However in the attempt to diverge Akko from the path, the power of the time portal caused Shiny Chariot to be given too much power that resulted in the idol accidentally destroying most of Japan. This cause Diana to be disgusted in herself and was driven to defeat until she was rescued by Bernadette.
Bernadette inspires Diana to continue the fight and succeeded. The two mounted a suicidal assault on Seishin Headquarters to stop Akko. While two forces battle it out, Diana and Bernadette entered the facility where the time spell was nearly ready. Diana and Akko clashed but eventually Diana won over the witch hunter.
Diana sent everyone away allowing Bernadette to seal the entrance preventing Akko and her men to enter. Bernadette completed the spell. Before she left, Diana expressed how proud she was of her alternate version's daughter which caused the Shiny Rod to relinquish itself from Diana and towards Bernadette, making her the new wielder of the Shiny Rod. As this happens, Akko burst through with her forces and rushed towards the portal but Diana entered it stopping Akko from completing her mission.
Diana returned to the past and now in the body from when she first appeared here. She stepped away allowing Akko to go to Shiny Chariot. With that, her time has been restored.