Tzim-Sha

Tzim-Sha (also known as Tim Shaw due to the Thirteenth Doctor mishearing his name) is the primary antagonist of Season 17. He is a Stenza warrior who plans to become the leader of his people.

Abilities
Like his fellow Stenza, Tzim-Sha has extremely cold skin and can kill humans or even Daleks simply by touching them. Because of his extremely cold temperature, he always wears armor to protect himself and maintain his body temperature.

Death
In the final episode of Season 17, Tzim-Sha is confronted by the Thirteenth Doctor who manages to injure him in a fight. The incapacitated Stenza warrior is seemingly incinerated by the Pyroviles who no longer see him as their God.

In the third episode of Season 19, however, Tzim-Sha is revealed to have teleported away before his incineration, albeit heavily injured from the Pyroviles' attack. He is found by the Ux who see him as their new God. He plans to destroy the Earth by sending it into a black hole, but the Doctors foil his plan by reversing the polarity of the neutron flow so that he is sucked in instead of the Earth.