Just think about that. The Stone is the well-known legendary artifact, that is assumed lost after the Saint Evrahard. It is well known, how it looks and what it supposed to do.
So, why Wyslynn's couldn't "miracliously found" the siant artifact, and present it to Vicarate, making as much noise as possible about it? Of course, the Stone would be tested, but even the Clyntahn would be wery cautious to claim that something that look like the Stone of Schueller and work like the Stone of Shueller is "shaing-wei dark magic"; even his own Inquisitors would hardly support him against the artifact of Archangels themselves!
And, when the Stone would be verified as authentic - or, at least, "as authentic as possible" (which would probably be the best that Group of Four could do to lessen the impact) - it would be natural to demand, that any witnesses about the "Charisian heresy" should be tested on the sacred artifact.
"Surely, the respected Grand Inquisitor would not oppose a purely formal verification of his claims about the Charisian heresy? Why, he shouldn't be afraid to testimony with his hand on the Holy Stone - after all, he is the Grand Inquisitor... Clyntahn, are you really refusing to testimony on Stone? Brother vicars, the honest man would not be afraid to lay his hand on Archangel's Own relic. Put Zasphar Clyntahn to the Question immediately - he is either a liar, or the heretic! "
