The Seven Priest

"The Goddesses speak through us to speak to you"
When you have a ring of seven who are considered to be the only link between the Goddesses and the world, there is sure to be a power dynamic that leans in their favor.  In the Kingdom of the Moons, the royal family funs the country, and the Seven priests run the royal family.  Being called as a priest is a life long calling that is only ended with death, it is a position people do not even bother to covet as only seven will take this roll and they will usually keep it for a good 40 years, making it a rare job to inherent.  
A new priest is chosen by the current priests each time one passes on.  Priests can be of any moon and any gender.  Often times there will be 3 priests of the first moon, 3 of the second and 1 of the third.  This is simply a tradition and is not a rule.  There have been times of 3, 2, 2.  Because the first moon takes up 70% of the population, there are usually more of this moon, with the second taking up about 30% there are still usually multiple priests of this moon.  Finally, with the third moon taking up maybe 1% of the population there is always one, but rarely more than one on the council.  
The royal family may make rules and rulings, but the seven priests can outright just say something different and that becomes the new ruling.  As long as they say the Goddesses told them, they can do or say anything.  They can have anyone, have anyone killed and do anything as they would like as long as the general population remains thinking they speak for the Goddesses.  They are outwardly very religious, but most of them honestly don't even believe in the Goddesses.  Corruption runs the church which runs the state.