I've been mulling this over.
I think that the Ceremony involves some sort of cannibalism like Bree described the Romans took part in in her Schoolwork in Summer video. That would explain iron pills and mystery shots. Also, the temple of Osiris at Denderah describes a ritual involving making wheat paste models of Osiris's dismembered body parts, which culminates in eating the models as a kind of eucharist.
http://en.wikipedia.org/wiki/Osiris Cannibalism is a recurring theme in these videos, which would seem odd if it was a dead end.
Given the connection between ancient Rome and Egypt during this time period, I find it likely that a cult of Romans could develop borrowing from the beliefs of the Egyptians.
