Juuyoku no Jousai by Fullfrap - Adult Sex Game

The story starts as an adventurer sneaking into an ancient castle in search of treasure.
In the ancient castle, she is violated by magical beasts, and enters a deep sleep.
When she awakens, she finds her soul has been separated from her body.
If she can't find a way to remove the beast's curse, her spirit will diminish, and eventually disappear.
Time is of the essence, she has to hurry. She must fight for her life!