Before Percy and co. set off for Liones, the boy goes off to hunt some game. However, he ends up in a mysterious valley....
Meanwhile, Donnie does some hunting of his own, but he misses his target. What his arrow hit wasn't a deer, but....
a giantess?! And she's a nun, at that! As Donnie apologizes for hitting her, some fairies suddenly appear, who address the giantess as
Dolores. They say a boy wearing a helmet wandered into the "valley of spirits", a place they refer to as a living hell.....
However, Percy, who subdued some of the valley's beasts, considers the valley to be a
paradise! 
However, off in the distance, he hears a voice crying for help. The voice came from a fairy in a nearby house, who's being tortured by some creepy dude who calls him his "guinea pig". Thankfully, Percy arrives just in time to rescue the fairy! However, this leaves him open to get drugged by the mystery guy! The fairies from Donnie's group refer to this youth as a "devil"..... who now considers Percy to be his new guinea pig. This mystery creep's name is revealed to be
Nasciens, the Mad Herbalist....!!!!
Something interesting to note: Dolores was the name of Diane's giantess friend from her gaiden chapter in NNT. I doubt that's a coincidence. As for that Nasciens dude, he doesn't look all that unfamiliar, either.....