Death's Head — David Gunn

In a far-future world, ex-sergeant Sven Tveskoeg is a vicious killer with a stubborn streak of loyalty. Sven possesses a fierce if untutored intelligence and a genetic makeup that is 98.2 percent human and 1.8 percent...something else. Because of his coveted gifts, Sven is drafted into the Death's Head, a group of elite enforcers ruled by OctoV, a tyrant who appears to his followers as a teenage boy but is in reality something very different. Armed with a SIG diabolo -- an intelligent gun -- and an illegal symbiont called a kyp, Sven is sent to a distant planet, the latest battleground between OctoV and the Uplifted, bizarre machinelike creatures. Sven knows he is a pawn, and pawns have a bad habit of being sacrificed. But Sven is nobody's sacrifice. And even a pawn can checkmate a king.