Zettai Shoujo Seiiki Amnesian summary:

Probably a spin-off of Kannazuki no Miko. Himeko, a devout Christian at a church, has lost her mother, father, and older sister, Chikane, when she was younger. While cleaning the chapel, she encounters a girl, who resembles her sister in face and name, impaled by a sword. Himeko is thankful to God for giving her another opportunity to see someone like her sister again, but she is then later attacked by another girl who say she possesses the "dragon's cry" within her body. Chikane vows to protect her.