Grey is a member of Clear Sky. He serves as their mechanic and is described by his comrade as an expert in his field. The player can visit Grey in the Clear Sky base for equipment repairs and upgrades. He also hands out a quest to find and bring back USB drives with upgrade data.
Trivia
The name "Grey" was one of three names confusingly used to refer to the Shadow of Chernobyl character Seriy before an early patch corrected it.