Slave — Kenneth Guthrie

A devastating war on the red planet Mars leaves one brave soldier maimed and on the verge of death. Death is a sweet ending, but the advanced races of the universes have other plans for him.

Rex Pain is thrown from the bloodthirsty wars of his people into the genocidal campaigns of the alien races. Forced to do their bidding or face further mind-destroying reprogramming, he must overcome powerful enemies on war torn planets if he wants to realize his ultimate dream: To return home.

This is the first book of the Space Marine Series written by master of Sci-fi Kenneth Guthrie. You may also enjoy Jupiter Wars (Space Marine #0), which is a prelude to this story.