Which blade oil should I use against the Wild Hunt?
Solution 1:
The correct answer was found in the Official Prima Guide - it is Elementa Oil.
Edit: my old link to the forum no longer works. There is a picture from the book in another answer in this thread. I can confirm that it's authentic and correct.
Solution 2:
I know this is old, but searching online led me to this. I'm pretty sure other people are looking for answers as well. So here you go. This might help.
Solution 3:
They are specters, so you should use "Specter" oil.