Regarding the night sacrifice, I believe that Vespers was indeed a Satyr, since the description mentions only him and the Naga as being cheerful, but I can hardly imagine the latter dodging a blow, let alone running away. They killed her with a blunt weapon (broke her ribs), so it was either dwarven hammers or an ogre's club. But we've already discussed this, I think.
As for the clue, the quote doesn't provide much concrete information to search for, and there are too many possible versions, some of which are not entirely clear... I'll look again and then decide.