After Jackdaw removed some of the gems surrounding her tomb, she was awakened by his tampering and killed him. Vincey later entered the tomb to alert him people were coming, but to his surprise found Iraxxa instead, telling him to speak. Another soldier came in and shot her out of fear. Telling him that was unwise, Iraxxa fired at the soldier, causing him to fold up into a cube-like shape, breaking his bones and killing him. She was about to kill Vincey before Friday walked in, giving him a distraction. Friday was Iraxxa's sentinel and she told him that he fulfilled his pledge, however he told her that they'd been asleep for a lot longer than was anticipated; 5000 years.
Not long later, the Red Coats were called to arms upon finding out the news of Iraxxa's awakening and all ran to her tomb as well as the Twelfth Doctor and Bill. Neville Catchlove in rage told his men to prepare their guns as revenge for killing some of "his" men, but the order was retracted by the true leader at the time Godsacre. Godsacre allowed the Doctor to talk with Iraxxa who tried to negotiate with her to give mercy to the Victorian soldiers. To her surprise, he's familiar with her species. He told her that the planet is dead now, and Friday reinforced his word. She asked for Bill's opinion as she is also a female. Bill later agreed with the words spoken by the Doctor and Friday, and told her that they saved Friday's life. However, she was enraged at how they treated him which caused the soldiers to aim their guns at the two. The Doctor tried to negotiate still so no more would have to die, telling them to fight for the future and not for a past long dead. Unfortunately for him, a soldier accidentally fired at her, causing her to grant the Doctor's wish for mercy - but with a quick death as her form of mercy. She fired at one of the soldiers, causing them to retreat.
After Catchlove fired the Gargantua which blocked off the doorway, Iraxxa began to awaken the dormant Ice Warriors. She stated that it would take time to revive all the Ice Warriors but enough were awake to attack the humans. She sent them underground and to burrow upwards as a surprise attack. Whilst the battle occurs, she continued to awaken the rest of the Ice Warriors.
Bill distracted Iraxxa whilst the Doctor began his plan with the Gargantua, telling her to talk woman-to-woman. Bill asked her why this had to be war, telling her they could stand together, but Iraxxa told her Mars stands alone. The Doctor set up the Gargantua to the roof, and told her that if they don't spare the people then he'd fire, burying the place and everyone in it in snow, meaning they could either live together or die together. However, Catchlove got her from behind with a cutlass to her neck, threatening her to repair his ship or he will kill her. She stood her warriors down and began to make way to the ship, before Godsacre appeared and shot Catchlove, saving Iraxxa's life. She questioned Godsacre's move to sacrifice Catchlove, putting them at a tactical disadvantage. He replied that he executed him, and in return she asked if he expected his life to be spared as a result of this action. He didn't, and expected to be killed and allowed it to happen willingly. Iraxxa told Godsacre it'd be her pleasure, but first he had a request for her to spare the humans and to not think of humanity by his or Catchlove's actions. Iraxxa told him that it was considered and that he'd die with honour and bravery and in the service of those he had sworn to protect - but not today, but in battle, the way of the warrior. She told Godsacre to pledge his allegiance to her and Mars and she'll ensure that he has the oppurtuinity. He does pledge to her.
The Doctor sent a message to Alpha Centauri in order to give the Ice Warriors a life away from their now dead planet, beginning the Martian Golden Age. Iraxxa spoke to Alpha Centauri, to which they said that they'd need a physical marker to guide their ships. (TV: Empress of Mars)
Iraxxa, being the Queen of the Ice Warriors was of course very commanding. She also seemed to care about the treatment of the Ice Warriors and would always retaliate to an act of violence no matter how much or how little damage was done. She put her Ice Warriors and her pride for them before any sort of alliance and protected them. She was described by the Doctor as a “very stubborn Queen”.
She also seemed horrified upon learning that her native planet was a barren wasteland and inhospitable after five thousand years of hibernation.
She was seen to be highly respectful towards other females, even if they were from other species, as she specifically asked Bill Potts for her opinion, valuing it highly among a room full of "noisy males".
However, in the end she did show compassion by sparing Godsacre's life so that as a soldier, he could fight again with honour. She also thanked the Doctor for kickstarting the new Ice Warrior's life, meaning she did learn to cooperate with foreign lifeforms. (TV: Empress of Mars)
Behind the scenes
While Iraxxa was the first on-screen female Ice Warrior seen, she was not the first in all media with other female Ice Warrior individuals such as Luass in the comic stories Descendance and Ascendance as well as Lixgaar in the audio story The Prisoner of Peladon. However televised media has been no stranger to the idea of female Ice Warriors either. In TV: Cold War, Skaldak mentioned having a daughter.
Prior to her proper debut in Empress of Mars, Iraxxa appeared in A Time For Heroes, a teaser trailer for Series 10 consisting of original footage. She was seen as a wrathful, ghostly apparition threatening Bill Potts, Nardole and the Twelfth Doctor at the end of a library corridor.