I like the 'Control Fertility' supernatural virtue, from societates, as it seems especially appropriate for minor hedge wizards and wise women and such throughout all of Mythic Europe.
It can do various things to affect fertility and health. I'm puzzled by one of the effects, though.
'grant a +1 or -1 Living Condition Modifier to aging (must last a year)'
The duration of these effects is one month at ease factor 9, plus +3 for every additional month, and to have an effect the aging one has to last a full year. So... 9 + 33, somehow they're supposed to meet an ease factor of 42 to add +1 to someone's living condition modifiers.
Let's imagine the most extreme of circumstances here... ability 10, specialization, puissant ability, favorable aura of 10, and presence +5. That's +28 to the roll... so on the stress die, a result of 14 is still needed. Not going to happen.
Vis can add to this as with other supernatural abilities (I think.) Thirteen pawns of corpus vis, added to that excessive set of circumstances described earlier, is just enough to guarantee the +1 living conditions modifier.
Maybe it's just me, but it seems like either it shouldn't be possible to affect aging with Fertility magic, or the effect should be easier or stronger. As is, it just doesn't make sense to me that the effect is even mentioned, as it's practically impossible to achieve and has an effect that's very well near undetectable.
Have I misread something?