This is an amazing anime, very unpredictable, you start feeling this is a classical fantasy moe all cutsy and then you get the gore, and then you get the desperation and finally you are deep in the horror of the different depression coming from resurection. Epic battles and gory deaths. One of my favorite reviews was from Chibi during the episode between Ren and the main character.
https://www.youtube.com/playlist?list=PL5k8kgVRPLo-LwhaaqnHWxy5CeAQ3bop1