Read manga: Last Order: Hitori Bocchi No Hyakunen Sensou

manga
Summary:

A post-apocalyptic world. Following her last order, the mechanical soldier Ria has been fighting an endless war for over a hundred years. With the people she was meant to protect gone, and her comrades-in-arms lost, Ria spends her days fighting alone.Then, a human appears before her once more..!?