The first episodes of this series started out with an interesting (if simplistic) premise: the Japanese discover a portal to another world, are attacked by an army from said portal, and go in guns blazing.
Beyond that the writers, directors and producers should be ashamed of themselves for the repeated theme of "offer my body for the good of the Kingdom" and at least one scene of sadistic rape presented in the anime (I didn't watch any further than that episode 13 scene).
Japan has a much-deserved reputation for anime underage sexualization / violence theme. This series does nothing to eliminate that stigma. I made it through 12 episodes of "suggestive" theme, until the 13th pushed it over the edge and took it off of my watch list. One has to wonder about the mentality of people who put such things in the middle of an anime series that up to that point gave no hint of such.
For the record, I'm a guy and found this offensive in concept and execution. It presents the worst of outdated Japanese thinking and culture: the way to solve a problem is to kill 100,000+ people outright because you can-- and women are to be used and abused rather than respected. Ignore the token female "power images" presented-- their primary purpose seems to be a mini-harem for the main character. This is sado-chauvanistic presentation that ruins a decent premise. Anyone with mature sensibilities may want to give this a skip.
Check out our gallery of the 2021 Golden Globe nominees in the leading and supporting acting categories, as the characters they so brilliantly played and in real life.