Lazarus war

Artefact is book one of The Lazarus War, an explosive new space adventure series from one of the brightest new stars in science fiction — perfect for fans of The Edge of Tomorrow, Alien and James S. A. Corey's Expanse series. Jack Campbell, author of the Lost Fleet novels calls it "a gripping read that moves at warp speed."
Mankind has spread to the stars, only to become locked in warfare with an insidious alien race....

For someone who has died and come back as many times as Conrad Harris, the nickname Lazarus is well-deserved. His elite military teams are specialists in death - running suicide missions in simulant bodies to combat the alien race known as the Krell. But now the Krell Empire has wreaked such devastation that military command is desperate for a new strategy. And Harris and his team are being sent on a mission that could finally turn the tide of the...