The wealthy family + was never identified. Soros replaced the Rockefellers on behalf of the Anglo-American establishment.
A guess why + has never been revealed is that it may be too close to Anglo-American politics and require preparation. It could, for example, be the Windsors, or a Nazi faction, or the Hapsburgs / Pan Europa movement.
FBI Anon said something similar before the election, which is that one family head died in Dec 2015. My guess: P2 head, closely allied to the Hapsburg.
The structure of the controlling finance families and the layer above them requires a lot moar digging, and probably shades off into CT land too much for present practical politics.