Iraxxa

Iraxxa is an Ice Queen who makes her first appearance in the fifth episode of Season 13.

Role
Prior to Season 11, she was captured and held hostage by the Cybermen, who threatened to kill her if Azaxyr didn't do their bidding.

Iraxxa is first seen in the fifth episode of Season 13, when Azaxyr asks the Cybermen to let him see her. Upon seeing him, Iraxxa reacts with disgust at seeing one of her followers working for the Cybermen. Azaxyr replies that he is sorry, and that if he doesn't do what the Cyber Controller tells him, the Cybermen will kill her. The Cyber Controller then shows up to demonstrate this by ordering Azaxyr to capture more humans to be converted into Cybermen. When Azaxyr hesitates, the Controller orders his 2 guards to remove Iraxxa from her cell and expose her to the heat which will kill her. Azaxyr reluctantly goes along with the Controller's plan and Iraxxa is locked back in the cell.

Throughout the rest of the season, Iraxxa is occasionally visited by Azaxyr and/or the Cyber Controller. The former of whom is regretful that he cannot do anything to resist the Cybermen without her dying, and the latter gloats to her about how the Cybermen will dominate the universe.

In the penultimate episode of Season 13, the Doctors show up and find Iraxxa locked up in her cell. When Azaxyr finds them with Iraxxa, he is about to kill them until the Tenth Doctor reminds him of Skaldak. Iraxxa expresses surprise that the Doctors know who Skaldak is, to which the Fifth Doctor replies that he was a great hero who gave his life to save the Universe from the Daleks.

After the Cyber Controller is killed in the Season 13 finale, Azaxyr releases Iraxxa, who promptly kills 2 Cyber-Leaders with her Sonic Blaster, which is much stronger than Azaxyr's Sonic Blaster. Once the remaining Cybermen are destroyed, Iraxxa returns to Mars with Azaxyr, planning to punish him for allying himself with the Cybermen. However, she states that his punishment will be reduced due to him going against the Cybermen in the end.

In Season 15, Iraxxa returns along with Azaxyr to help the Doctors stop a Dalek plan to spread Dalek nanogenes throughout the Universe. Once the nanogenes are destroyed, Iraxxa destroys the Dalek Prime Minister by shooting him with her Sonic Blaster.