Let's assume a magus above any suspect publicly announces his intention to re-discover the lost magical secrets of House Diedne ("Sodales, while this House and its horrible practices of human sacrifice have been justly expunged from our Order, this caused the loss of worthwhile magical secrets concerning the mastery of flexible spells, which should not be lost to the eventual advancement of Bonisagus' system. It is my awowed purpose to bring them back to light")... and succeds, eventually creating a set of Mystery Initiation scripts for Virtues like Diedne Magic, Faerie-Raised Magic, Life-Linked Spontaneous Magic, Enduring Constitution, Subtle Magic, Quiet Magic, and effectively creating a new Diedne-like Exoteric Mystery (most likely, a new set of Merinita House Mysteries).
It might be genuine, or a well-crafted plot by a mage with a hidden Diedne lineage to pull a "True Merinitae" and re-create a socially acceptable form of his lineage.
What would the reaction of the Order be ? And if a publicy-acceptable form of the Diedne magic Virtue is created this way, how the Virtue should be modified, since it can no more incorporate a built-in Dark Secret Flaw ? I was thinking of substituting it with Hedge Magic or Infamous.
I suppose the reaction would be dependant on several factors.
First did another House, say the Tremere prop up charges to initiate a war against the Diende? If so, and some ancient master still knows this, they might be opposed to the research simply on the grounds that House Tremere's Dark Secret will be revealed.
Second, any Christian Magus regardless of House maybe against this research because you casually mentioned human sacrafice and fairy magic. Depending on the kind of Christian they are, the premise of exploring these ideas could lead to strongly opposed knee-jerk reactions.
Third, it depends on how organized your version of the Order of Hermes is. In our game we have something simular to a centralized government which results in a system that would allow such information to quickly spread across the Order. However the same system would debate the issue so long, you would likely have finished developing a new Mystery by the time the government came to a consensus.
If your game is more simular to canon Ars 5, the information may spread across a Tribunal, perhaps even the Order. But unless an individual magus is not only offended, but actively takes an interest in stopping you, I think the exploration of such magics would meet with mild indifference.
So I would think about the politics of your game. How centeralized is your game? Is the process of looking for the information and an attempt to stop this search the point you want to explore? If so, then someone is against it. If it isn't, then it isn't contested.
Another great option is no one cares and then after the Mystery is created it leads to significant changes in the Order. Then you can explore the ramifications of introduceing something new to the world of Wizards.
All of this assumes that's what your interested in. If you just want to add a new list of powers to the game, I'd just talk it out with the troupe.
Hmm, I follow the opinion that the persecution of House Diedne was entirely unwarranted and the result of rabid ideological prejudice of the part of House Tremere, so indeed they propped up charges. But I would not define it a "dark secret". It is all rather plain. Many contemporary mages are of the opinion that Tremere started an unwarranted war, but since Diedne are extinct anyway, and Tremere are still around, they do not push the issue.
But would Tremere push the issue ? And what form would it take ? Subtle harassing ? social hostility ? Wizard's War ?
This, I fail to see your line of thought. The character would propose and follow a line of research to rediscover Diedne magical secrets of lexible magic, not reinstate human sacrifice. I can see the reason for Tremere hostility, but not for Christian one. After all, Christian mages dig out secrets of pagan magics all the time.
So the main issue would be Tremere hostility. I see.
Actually, I need to wait and have the full Mystery rules, since as of now, I have no idea how much it would take for a talented or specialized mage character to develop a complete Mystery (i.e. develop something like at least 5-6 Script Initiations). I.e. it is something a PC can pull off in a reasonable time, if he really cares, or not.
But yes, I would like to explore what ramifications would be for introducing a significant improvement to the default level of magical advancement. Actually, there are two kinds of novelty I would like to introduce: permanent Creo healing without raw vis (this would work best through original research, I think), and reintroducing House Diedne magical secrets and ways in some way into the setting (this would work best through a Mystery Path, I think).
The published material says that the diedne were very secretive and their enimies accused them of making deals with the infernal. The published material never tells us whether this accusation was correcet or incorrect and hopefully never will.
If many people see Diedne magic as tied to the infernal then it isn't unlikley that some of them will seeany attempt to recreate Diedne magic as dangerous and unwise.
Well, as one may infer, I'm making an definite choice, in that those accusations were specious and slanderous Tremere propaganda, and while their human sacrifice tradition was questionable (no more than death penalty, though, since they only acutally used it on criminals and volunteers), they definitely did not warrant persecution nor extermination. Tremere are the bad guys in my version, acting out of bigot ideological prejudice and power thirst.
Hmm, but how much this would matter ? I mean, Tytalus were caught red-handed at real infernalism, but after a purge, the House was allowed to exist, and now stand as equals among equals. The accusation against Diedne was much more questionable to begin with, even in canon (e.g. canon strongly indicates that if Ex Misc votes had been present in that fateful Tribunal voting, Diedne would have won the case, and Tremere would have been cast out instead: an alternative setting that I'd been sometimes toying with exploring, since it would give a pattern of Hermetic magical practices that I would find much more satifsying: druidical magic, instead of the ho-hum Borg House, even if 5th ed. version is slightly better).