Timediver's Dawn (Timegod)

the long version

The star-traveling Frost Giants have destroyed the government and much of the world's population. Colonel-General Oden Thor and his ConFed Marines are chief among the few organizations trying to restore order. Sammis joins the Marines for the food and relative security. He discovers that he is a timediver, one of a handful who have the mental ability to cross vast reaches of space and time in an instant. As such, he works both with and against Odin Thor to preserve his people and fight the Frost Giants.