Ok guys, since I'm following this thread, and the thread in US forums since they started, I am going to anticipate as well.
So as I tried alot of things as you did, I have ran into something
I am on a par with everyone saying that the trigger is in BI.
So there is this thingy in Black Rook Hold where you can click on it and you get the Buff "Wandering Soul"
We are indeed talking about a trigger for the hidden artifact.
I know the buff is for Maw of Souls achievement, but as I saw the puzzle for Kosumoth, I believe it might be something we should try around the BI. I'll have a try taking the buff to "famous" places.
What do you think about it? Probably post it in US-Forums as well, since I'm EU, I can't, sadly.
postet it in the false forum b4, sorry