Hundreds of years ago a dungeon was built to contain one of the greatest treasures in history. A Sword That Slices Through The Past. This sword can be used to erase parts of history or rewrite history entirely but it is unpredictable and random and it often reflects the deepest darkest desires of man. Take for example one of the first to use this sword; A man who wanted to use the sword to erase the sins he committed against his god, when he used this sword it instead rewrote the past so it would impossible for him to do anything but sin by turning him into a succubus queen.
But most never make it far enough to reach the sword. The Sword is guarded by a ever shifting labyrinth full of monsters that will physically transform intruders until they are unrecognizable sex crazed nymphos.
But if you can manage to reach the sword to erase the past you may find it is not what you wanted.