Unfortunately Deficient technique: Creo speaks against that. There are others with Perdo, I know, but I would be interested to figure out mechanics for destroying abilities if there are any hints in the books. HoH: S is pretty clear on creating abilities (no one has yet figured it out, though hermetic magic should allow it).
What would the effect on combat be anyway? I suppose a MuMe version using some existing thought or emotion would have a similar effect at a similar magnitude...
Much more precise yes and thanks. What I wanted to say was that there is no apparent reason that hermetic magic can't do it. My actual point though was that HoH: S deliberately focuses on creation of abilities when saying that nobody knows how to do it.
Unfortunately there is no example of a PeMe effect on abilities (other than Agnosia). Agnosia is base 3 and looking at slightly higher bases I'd say removing abilities could/should be possible.
Granted, as story guide I would probably limit that to temporary effects because of game balance.
That - overcoming this limit - by the way would be quite an interesting endeavor for a Bonisagus or maybe a Verditius. Imagine a weapon that grants the wielder the capability to use it.
Have you considered DISSOLVING THE WALL OF SHIELDS (Houses of Hermes : Societates p70) ? It seems to something really close to what you are trying to do ?
So it is too narrow to affect fighting I suppose. The base 4 of it might indicate though that it had to be at least base 5 to have the effect I'd like to have
I think it is going to be either base 4 or 5 and this will have to be decided upon by my troupe. There are good examples for both. Thank you all for the pointers, I guess they at least doubled the examples I have at hand.