In the Diedne-rant-thread (which seems to have exploded almost overnight, since my first reply in it), I keep hearing references to "Shadow Flambeau". What and who were those, and in what book are they described? Is it even 5th ed?
I have all three 5th ed HOH books, but might have missed something in reading them. My mooching gaming group has been hogging them since we started the preparations for a new saga, with some noobs along the old veterans.
The Shadow Flambeau were a saga arc presented in the Iberian Tribunal book. They were mentioned in passing in the infernal book as one of the example characters was a reworked character from the Shadow Flambeau story (but now without the particularly egregious example of the puerile silliness that white wolf made a habit of sprinkling through some of the later WW Ars Magica books).
Ok. I thought they were a pre-5th ed thing, since I've read the Flambeau chapter in HoH:S twice.
But what were they - in short terms - about?
They're in the old Iberian Tribunal book. Basically, they were a group of Flambeau that turned to diabolism. The rest of the Flambeau turned on them in a very brutal purge.
-Ben.
And cleverly changed, by the way. Craft Hex Toys, for a witch 
Very Great 
IIRC, some shadow flambeau are supposed to have survived, aren't they?
In fact the story was less clear cut. They ARE diabolists, but they have a reason for it: hate.
The flambeau of Jaferyia (IIRC) turned to diabolism in their hateful drive to kill all the muslim magi they crossed path with. In that edition, Flambeau had been killed by muslim magi, and the setting said that flambeau had quite an animosity towards muslim magi (including those in the OoH!!). The Shadow Flambeau simply put that hate to the extreme and fell into diabolism as a way to get more power to kill enemy mages.
They were extreme crusaders in that sense. There was even a hint that the "St James on a white steed" that showed the reconquista christians the path to the muslim encampment at Las Navas de Tolosa was in fact a disguissed member of the Shadow Flambeau (Mu and Cr Im, it would seem).
if you removed most of the random demons, the Iberia tribunal contained some good supernatural ideas, in fact. The Shadow Flambeau played an impoertant role in my Iberian Saga... And they were never discovered to be diabolists!!!! 
I played them as way less cartoonish, that is for granted. The craft sex toys gfal remained though, and one of our companions even went to bed with her.... painfully She is no more weird than most magui of the order, after all. I simply made her into a nympho dominatrix, but that was additionally with her partying with servants of hell on Saturdays.
Cheers,
Xavi