An unarmed berserk grog attacks an enemy magus.
The mage has their Brawl skill, plus increased Soak due to Corpus score to survive the hand to hand assault.
What about if the attacking grog is magically assisted. Does the defending mage's Parma help in all cases?
If the assist is Muto to give the grog something they don't have eg claws, I would say Parma yes.
Rego to move the grog into position, maybe unless it was Vilano's sling effect.
Rego to control the grog's thoughts? It is the grog's physical body attacking the mage.
Rego previously to file the grog's teeth extra sharp, probably not.
Creo to enhance the grog's physical nature within natural limits? If it is an ongoing effect the Parma should be a barrier? An instantaneous ritual, probably not.
An invisible grog? The Perdo has taken something away from the grog, but otherwise it is all natural grog doing the attack. I suspect that Parma blocks the grog.
See ArMDE 07-Hermetic MagicThe Functioning of Magic Resistance:
An invisible character cannot touch or exert physical force on the maga, even if the invisibility spell had Personal Range. The maga feels the warning that something has been resisted, but feels nothing else. See the magical bridge examples, earlier, for further discussion.
Grog can be invisible and will not be revealed unless the invisibility effect is resisted. If your Grog has a competent master, then his penetration total for the PeIm spell would be significant even without an arcane connection to the target mage. Also, grog or his master can drop the invisibility at the right time... such as when target magi is alone in the room.... or so he taught. The tingling thing only happens when the invisible character tries to touch the Magi protected by Parma.
Things that do not interact with the MR are not resisted. If the Grog is enhanced with Cr or Mu effects but hits with a mundane sword the poor Magi, there is no Parma to save him.
Magi in general probably want to have a ward or two handy, especially for wizards wars. Three core ones being:
Halt The Piercing Shafts ReHe(Te) 25 - Source: Magi of Hermes, 50
Sword Ward ReTe 20 - Source: Through the Aegis, 78
Ward Against The Curious Scullion - ReCo 20 - Source: Convenants, 104 (Modified to personal range)
With these 3, the Magi is fairly immune to Grogs. To avoid warping, invest a version in the familiar bond or use only when under threat.
Also of note is that a Dagger of Silence (T/M/Ind) version of Wind of Mundane Silence of level 30 +15 Pen for an effect level of 45 would dispel all above wards of a magi that has a Parma of 5 or lower and has less than 5 in Vim. Serfs Parma on Aura interactions. Now, giving such a powerful minor item to a grog will have Quasitors rise an eyebrow. An evil Master might just give the Grog a dagger of Parma Dispel which requires only a level 5 +15 Pen for a total effect level of 20 to do the same but just to the Parma.. but will probably have th Quasitors rise two eyebrows. Evil Magi then has two full minutes to handle the target Magi.