Hey, where are you finding these mastery options for ritual spells?
Not quite sure what you mean. There are mastery options in each of the Houses of Hermes books.
This pdf combines them all in one handy-dandy location. germanitas.org/rpg/germ/down ... astery.pdf
By the way, if you dangle Ceremonial Casting in front of Ra'am you can probably lead him almost anywhere...