OK, let me get it off my chest straight away - I do not approve of ANY official origin for the Phantom Stranger. And making the Question a mystical character also doesn’t leap up and kiss me on the mouth. But I’ll let those pass.
Cause everything else in the New 52 was stellar, and has me VERY keen on hearing more.
The Black Room is a neat idea, a fairly standard trope - a vault/museum for impossible objects - but it makes sense that such a thing would exist.
I immediately noticed the Haunted Tank, the Medusa Mask and what I must assume is the Gamma Gong. The chandelier could be from Red Jack’s mansion, assuming the Morrison Doom Patrol adventures were still in continuity. The Spear of Destiny has been used in DC adventures as far back as All-Star Squadron, and the Black Diamond is surely the one that contains Eclipso. And is that the corner of a Red Lantern there in the background?
From here on I’m guessing. The suit of armor is too small, but could be that of Brian Kent, the Silent Knight, or perhaps one of the order of St. Dumas? The ship could be the hull of something pedestrian like the flying Dutchman, or that of the Viking Prince.
So, how many things can you pick out in the Black Room?