
Back in April, Pablo Schreiber was cast as Master Chief and now Showtime has made another big announcement for their Halo TV series. Natascha McElhone will have two roles, Dr. Halsey and Cortana.

In a press release by Showtime we hear about Halsey and Cortana.
McElhone will star as two characters — Dr. Catherine Halsey, the brilliant, conflicted and inscrutable creator of the Spartan supersoldiers and Cortana, the most advanced AI in human history, and potentially the key to the survival of the human race
Other actors cast for the series are Shabana Azmi, who will play Admiral Margaret Parangosky, the head of the Office of Naval Intelligence and Bokeem Woodbine, who played Shocker in Spider-Man Homecoming – will play Soren-066. This last character is a privateer who is morally conflicted.
New characters in the Halo universe appearing on the Showtime series are Bentley Kaiu as Spartan Vannak-134, Natasha Cuizac as Spartan Riz-028 and Kate Kennedy as Spartan Kai-125.
The Halo Showtime television series is set to premiere in the first quarter of 2021.