Some thread necromancy, as I don't want to derail the thread this was from.
I've always thought Mercurian magic, especially with it's spontaneous magic issue, is one of the weakest Great virtues. People want an NPC in the covenant with Mercurian, but don't want it themselves. Would it be a worthwhile game balance option to add this to the errata?
"You automatically master every ritual spell you learn or invent. All your ritual spells start with a 1 in the corresponding spell mastery ability."