Saw this as a recommendation and decided to watch this series. It began with a hero who was out to defeat the Demon King who turned out to be a Demon Queen who had other ideas in mind. She proposed to Hero that they should end the war between humans and demons.
Her proposal worked as she showed him that there were underlying issues on hand and Hero joined her cause. Throughout the series, all the characters were just known by their titles or occupation. Rather unique to this series.
Hero had amazing powers that he used to resolve the issues on hand while debating his affection for Demon Queen. Yet, it was this strong affection for her that helped her when she returned changed from her renewal trials in the Demon World in order to maintain her status.
As the series progressed, Hero reunited with his previous team and convinced them of his cause. He was also beloved by Female Knight who had great fighting knowledge and powers. The old team started joining forces again to unite the humans and demons.
I rather enjoyed this short anime series.