Junketsu no Sophia ~Yami no Seieki o Seijun Naru Elf no Chitsu Ana ni~

An evil shade gradually invades peaceful country.
Demons and their king are awaken from the seal that was casted upon them 1000 years ago.
Sophia, a child of elf, together with Tanya decided to form a group with humans to fight with this invasion.
An evil king Galdo (a main character controlled by yourself) tries to make every human under his control by taking Sophia's body with evil pleasure.

[From dlsite]