I have finished this quest now and can confirm it gives the primal quirk crystalline resistance.

Righto, so you all know how to get to SDC right? well! from the enterance to the animals you head north until you find this hex.



On this hex you type in command mode; down. You do not climb down and you should end up here:



Wunderbar! now you head south east to the NPC to start your very own quest!

Basically this NPC tells you that these Wraiths wearing what you may have seen in BDC, the specter cloth need to die and so do the specters! he will give you a nice defence buff he claims so let's get bashing in some ghost skulls. Once you have obtained the 5 Wraith cloth you need to kill Specters, where are they? right here slightly to the left of the NPC. Climb down here.




Once below you should see this... ( It is NOT climb up to go back up it is just command mode ;up



Head north and you should find Specters and Marburn, I am level72 and cannot speak to him yet.



Kill the viewed specters until you have collected and handed in all 5 and voila, quest complete. You now have the crystalline resistance primal quirk.