Keyword Exoskeleton

Major Bill Cage is an officer who has never seen a day of combat when he is unceremoniously demoted and dropped into combat. Cage is killed within minutes, managing to take an alpha alien down with him. He awakens back at the beginning of the same day and is forced to fight and die again... and again - as physical contact with the alien has thrown him into a time loop.

In 2014, aliens revealed themselves to request trade with humanity. In exchange for limestone, they would provide a consciousness-controlled general-use robot known as an "Exoframe." Cheaper than an aircraft, tank, or firearm, and easy enough for anyone to operate, the "Exoframe" spreads change throughout the world in the blink of an eye...