Heroes 6 - Discussion

Please help, I really need to know. How do I unlock the 5th Dynasty slot? Initially, we only have 1 slot available. On the altar, at the bronze and silver ranks, we can purchase the 2nd and 3rd slots, and the 4th slot is available in the Jubilee. Someone mentioned that you can buy another one at the gold rank, but it's not available for me. Does anyone know what's going on? I have both DLCs purchased, but I haven't bought Shadow of Darkness.