With in the Thaumaturgy Tree and in the Subnode Omnious Materials there are 2 nodes that are suppose to increase the amount of Ominous transmutagen you get but this is bugged to be working for Mercurial when breaking down Mercurial materials. Grey and Red need swapped in the code.
After some testing, I don’t believe mercurial and ominous bonuses are swapped. It seems that the nodes that read “You have a chance to receive additional Ominous Transmutagen when performing acts of Thaumaturgy or Transmutation” and “Acts of Thaumaturgy with Ominous materials now yield a small amount of Volatile Transmutagen” both apply only to thaumaturgy with Mercurial materials instead of Ominous Materials. The same is true with Mercurial Materials bonuses applying to Volatile Materials. I don’t have another Thaumaturge with points in Volatiles Materials to test this, but I suspect Volatile Materials bonuses will apply to Ominous Materials instead. So it’s a 3-way shift:
Ominous Materials bonuses are applying to thaumaturgy with Mercurial Reagents instead of Ominous Reagents
Mercurial Materials bonuses are applying to thaumaturgy with Volatile Reagents instead of Mercurial Reagents
Volatile Materials bonuses are applying to thaumaturgy with Ominous Reagents instead of Volatile Reagents