Delphox

Ms Delphox was a clone of Madame Karabraxos and the Head of Bank Security at the Bank of Karabraxos.

Bank of Karabraxos
In order to ensure the loyalty of her staff, Madame Karabraxos would clone herself several times and place these clones in key positions within her company. She would place at least one clone in every facility she owned.

Miss Delphox was one such clone who was placed as Head of Security in the Bank of Karabraxos, the company's main facility. She was ruthless and efficient in her job, but also lived in constant fear of her master, as Karabraxos would kill and incinerate any clones that failed her. (TV: Time Heist)

Death
When the Doctor and his allies infiltrated the Bank in order to free the Teller and its mate from captivity, Delphox was determined to stop them at all costs. She sent the Teller after the Twelfth Doctor, Clara Oswald, Psi, and Saibra to stop them from infiltrating and robbing the bank, but was fired and incinerated by Karabraxos after she failed to do so. (TV: Time Heist)

Personality
As the head of security of the Bank of Karabraxos, Delphox was utterly ruthless, merciless and efficient in her job. In public, she would always carry herself with an air of confidence, poise and arrogance. She would act seemingly charming and affable especially when the Teller was about to devour a person's mind, displaying a complete lack of empathy.

Behind closed doors, Delphox lived in perpetual fear of her master and would show visible signs of nervousness and unease at the mere mention of Karabraxos' name. Her life literally depended on her job and she could not afford to make any mistakes, as this meant she would be deemed useless and killed. (TV: Time Heist)