Super Dimension Century Orguss 02

Years of political tension and mistrust between the two rival nations of Zafran and Revillia escalate to the point of war. Each nations solution: to gain possession of Decimators, the same ancient robots of war that nearly ended all life on the planet 200 years before. As the war ensues and the leaders of both nations become reluctant to surrender, only the desperate plan of Lean, a young cadet, and Nataruma, a psychically gifted young woman, to alter the timeline of events 200 years before stands the chance between humanities survival or absolute destruction.

Synopsis from Anime News Network