Hey Dymtra!!! I mentioned wanting to make another character and I have some ideas for him, but I wanted to make him a member of The Abbey Nightshade, and I was thinking a little on the religion and made up some extra stuff?? So here my ideas for it - please feel free to add/take away stuff u don't think fits, but yea!!!

SO:

buddhism as a base - The Belladonna reincarnates after every life time and apparently holds the culminative knowledge and wisdom of all previous Belladonna. The Abbey doesn't see this as a contradiction to their belief system, as the Belladonna is not a [i]deity[/i] as such but a normal human being.
The Belladonna is the avatar of justice
The Abbey is dedicated to helping those in need as it rallies against the dark and uncertain forces of the universe/magic, and so have many orphanages throughout all the kingdoms
But the orphanages also serve a purpose, to raise children to fight against perceived enemies e.g. witches, demons, magic etc etc
They have a strong community feeling and will protect and induct anybody who wishes to join their order 
Highly developed medicine and developed anesthesia due to humanitarian aid focus and connections across the empire
Symbol is the belladonna leaf, traditionally gold and worn as a necklace or cloak pin

Multiple practices and traditions in the cult due to schisms of practise. Different cells may have a leader of their own who co-operates with The Belladonna through messengers and letters

A lot of travelling cultists are clerics who perform marriages and help the wounded are also used as judges, and travel through towns periodically to deal out the Kingdoms laws

Thats about all I have so far, but yes, please feel free to corroborate!!! Also, I have a friend who wishes to join in - its not too late for that, right?