Talk about it here.
Originally, the suits were used to keep the villagers of the planet alive, as they were dying due to the fallout of the Last Great Time War. Cole originally only made one suit for Elidh's father, Anvar, who was almost dead.
However, once Cole had created enough suits for all the villagers and forced them all into one, for their own safety, they became their own creatures and tried to take out the Master and Cole, in a desire for revenge. The Master and Cole fled in the Master's TARDIS before they managed to kill them. (AUDIO: The Sky Man)
- Writer James Goss confirmed on Twitter the name of the enemies in this story are the "Retribution". With their creation being The Master's deliberately intention to create a paradox he could later exploit. 
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