Telos Minor, the icy twin planet to Telos Major.
Telos Minor is an ice planet located in the Telos system, teetering on the edge of League-controlled space. The planet was thought to be uninhabited until a race of crystalline life forms was discovered there. The Cybermen attempted an ill-fated invasion of this peaceful planet, only for the majority of their invasion force to be destroyed in orbit by the surprisingly sophisticated Telosian Armed Forces. Those who did mangage to land either froze to death or were killed by the Telosians using high-powered energy rifles similar to Covenant Plasma Weapons. Telos Minor has a twin planet that is closer to the the systems star, Telos. The twin planet is known as Telos Major.
The Cybmermen on Telos.