Longevity rituals are kind of the ugly ducking of the Ars Magic item design process. Initially they used a Creo Corpus total, but that was boring because it meant any sane magus eventually became a Creo Corpus expert. Now it has the odd effect of making most magi look younger than me, and so you get this odd “Twenty-something drama” look to Grand Tribunal, which is not really what we want. May I offer a counter-suggestion?
We know that Longevity Rituals make people sterile. This was, initially, to force magi to take apprentices as their children, but that doesn’t work at all because most magi have their children well before 35, which is when most take their potions (or do rituals). It’s just a sort of odd, historical feature. That being said, there’s a way to make it work.
Longevity rituals should be, in my opinion, a Exoteric Mystery of the Order. Let’s run some numbers!
What we are looking for is basically the Unaging Minor Virtue. Sure, it has some problems, and we could posit that the way to get around those is a Major Virtue, but those are the sort of special things for which you Ascend into the Hall of Heroes, or Become a faerie. Let’s just work with Unaging for now. I assume the Cult Lore of the Order of Hermes is Magic Theory, in this example.
Mystagogue Initiation total = 6 (Presence 0, Magic Theory with specialisation 6, although better is clearly possible.)
Special place and time: there are certain places designed for teaching this virtue, and House Bonisagus controls them: The Womb of the Order, for example, or the covenant which invented modern Longevity rituals in the Alps, and has a titan chained to a slab. +3
Symbolic aptness of the rite: +3. I’m not sure what this is, and they might vary. Cutting a sheaf of grain? Let’s assume poetry and move on.
Minor Ordeal +3: The candidate is rendered sterile. (treated as a minor Flaw, but you could also argue that this isn’t much of a Flaw and is instead a Sacrifice)
Unique Quest: +6 The character must go to considerable effort, and face danger, to collect items symbolically suited to his birth and life, so that these can be mystically transformed into part of his spirit during the rite.
So, I was trying to reach 18 and I’m already at 21. Mission accomplished there.
With another 9 points, I can justify something which not only hides the effects of age, but gives an aging roll modifier (say, a fraction of your highest Art score?). How can I get my 9?
Well, the way to do it is to suggest that the Longevity Initiation is not the first: the first Initiation is into Parma Magica, and it has as its Ordeal taking the Oath of Hermes, which is effectively a Major Flaw. As the first Initiation after the Parma Initiation, that’s -9. And that, as they say in tennis, is game!
So, we now see the Parma as a Mystery Virtue, followed by Longevity. What other virtues do the Bonisagus cult offer? The way Mysteries work the most efficient way on from here is to have at least two, possibly three, Virtues that lead off from here. I was thinking Certamen, and discarded it as basically trivial the way the game is now designed. I’d like to suggest that this be a new milestone for taking apprentices. You don’t need 5 in every art, you need a teaching Virtue from the Bonisagus masters. Well, not need, but you’d perhaps find it desirable? Perhaps the final one lets you write your memoirs skilfully?
Chip in in the comments!