Death's head - David Gunn

Few survive the cage. Fewer still live to face the whipping post. But insubordinate son-of-a-bitch Sven Tveskoeg does. As this ex-sergeant in the Légion Etrangére feels the first lash fall, he sees the desert tribes attack - and watches them slaughter his comrades before his comrades can kill him...

Rescued from certain death, Sven joins the tribes. However his ruthless skills have come to the attention of an élite special ops force, the infamous Death's Head. 

They want Sven to help them out with a little 'local difficulty'. He knows he's a pawn in a dangerous game - and pawns have a habit of being sacrificed. But Sven is nobody's sacrifice. And even a pawn can checkmate a king...