The God Mars Book Five: Onryo - The God Mars, #5

The God Mars is a pulp-style science fiction series set in a rich world of varied cultures and colorful characters. The series plays out a partially-terraformed Mars, a half-century after a man-made disaster cut thousands of colonists off from Earth, and the fear of a rampant nanotech plague prevented rescue. Left to survive for generations with few resources, the various groups develop unique new cultures at different levels of technology, ranging from the primitive to the frighteningly advanced.
But all are trapped in an escalating war between an oppressive Earth that's terrified of potentially infectious nanotechnology, and invincible superhumans-both heroes and villains-who claim to be from a nightmare future caused by that technology. In Book Five: Onryo, a terrifying new nanotechnology weapon threatens the lives of every "Normal" living on Mars. Meanwhile, a young adopted Nomad warrior finally learns the truth about his birth parents and where he comes from, but at devastating cost.
And the technological ghost of a murdered scientist returns to seek bloody revenge for the deaths of his wife and child.