Imagine a spell that creates a block of ice or wood or stone around the target in order to a) destroy the line of sight b) immobilize c) suffocate her. I'm sure this has been thought through somewhere, but I didn't find it.
What I found is an ice freeze spell in Societatis (Flambeau) which is ReAq and ignores resistance (but the water is natural - not magical)
There is also the wooden block spell from LoH that inspired me to thinking about it.
My feeling for balance tells him that either a finesse roll or penetration is needed, but I'm a bit uncertain.
(Serf's parma ON)
IIRC those are immobilization spells. They surround you around an inch from your skin, so they do not need to penetrate. However, they prevent you moving. If you want to cast a spell you will need to do it without gestures. You cannot die from their effects, right? So they trap you, but cannot damage you directly.
That's pretty much an official rule, see AM5 p.86, the last sentence of the first column. Basically, either you are throwing the spell directly at your target, and MR applies, or you are trying to put it near/around/on top of said target, and that takes an aiming roll. Of course, in some cases that aiming roll is a formality (creating a storm over someone gets something like a +24 to the aiming roll, a guaranteed success unless you botch your Finesse roll)
So you CAN create a block of... pretty much anything you like around your target to immobilize it, and bypass magic resistance at the cost of an aiming roll. If the material is itself damaging (cold damage from ice, for instance) it won't damage the target unless you also penetrate, but it will immobilize it.
For more example, you can look at HoH-S, the Flambeau section, it has a sidebar with a number of common spell that bypass magic resistance, including Weaver's Trap of Webs and Trap of the Entwining Vines, which both immobilize, or at least hinder, the target even if they do not penetrate.
There were some comments on that in HOH: Societies, IIRC. And in the forums. IIRC the final conclusion was that no, it would not suffocate. In Mythic Europe you do NOT need to breathe oxygen. Breathing is only relevant to get rid of body heat or something like that (can't recall my Art and Academe now), so as long as you have half an inch worth of air, it is enough for the interchange to occur. You would still have problems using gestures while inside the wood sarcophagus, but that would be it.
Serf's parma all along though I can't recall the exact discussion. This kind of spells have never been used IMS.
I treat Parma as flexible enough to defend against indirect attacks like this. Magic doesn't always work in a spatial or linear fashion - notice how all the ranges are determined by sensory perception and not distance - so I don't see any reason that moving a spell one inch from the target should bypass their protection.
Ah my bad. Well, you have 5 turns between each deprivation roll, so you should pass the first minute without suffering any problems. From there onwards the real problems start. But hey, you are a magus. If the challenge is not over in 2 minutes you are screwed anyway