You can't find the Masters themselves (this side-quest was supposed to set up my original plan for the Halloween update, but I had to pivot my plans), but the quest as it is now just needs you to either destroy or restore the Nithercott headstone. You can get the resources to repair the Nithercott headstone by destroying the headstones at the ruined Estates in the swamps, but just as fair warning, I do intend for there to be long term effects depending on what is done with the various headstones in the second act of the story.Thanks, now if I finish all the content, the mission to find the lost masters I assume is in process, right? or if it can be finished?
I would recommend some form of checker for completed missions.
I won't say much more than that for now to avoid apoilers, but the short answer is that it can be completed, yes.
There is also a Quest Tracking option on your war table. Last time I tested it, Melissa told you what was relevant for the Missing Masters side quest. If something isn't mentioned there and was earlier, it should be complete. In either v0.5 or v0.6 I intend to make that option mobile with the Homing Stone.