User blog comment:MDGeistMD02/Which Witch is Which?/@comment-3242762-20131127200422

Final Solution

Ok, to finally put this to bed. ALL witches are triggers EXCEPT the scout (who I now believe to be called Naria, for anyne interested in minor characters). There is no one witch that you can avoid incapacitating in some way that will prevent the attack (except the scout). This includes the "trap" witch, too.

Detection has nothing to do with the attack either, avioding the witches will still result in an attack. Also--and thanks to a random anon--the four witches who attack the Undine will assemble in the weeper area prior to the attack. (With some extra dialogue for anybody interested).

Mission Complete.