In any case, here goes...
Magical Cats are listed as having Ambush Predator. Do they need to spend their XP from season on the stealth and hunt granted from Ambush Predator, or does having the Quality grant the abilities?
Airy spirits... they seem to represent a significant number of things. If I'm judging this right, you could collect whole queens of vis by bringing these spirits up and killing them. It sounds like just about everything that remains in its natural form has at least a pawn of Vis to it.
What are the detrimental effects of this? Are airy spirits, in fact, the sentient/sapient manifestation of fluid Vis itself? Would killing them on a grand scale be detrimental to life as a whole?
Magical Animals must spend experience on the abilities of their species (pg 56). See also the Aelous example (pg 34).
On page 110, it clearly states that hermetic magic can summon or control airy spirits using the Rego guidelines and with access to certain mysteries, bind them into magic items. Two other possibilities -
Airy Spirits cannot manifest physically and thus can only be slain with apotropaic magics (which leave no vis behind).
Airy Spirits are part of a magical aura, so rendering them down for Vis reduces the aura. Expending the Vis reinvigorates the aura, but if enough Airy Spirits are "sequestered" as raw Vis, the aura will decline.
RoP: TI - page 33 - Demons' and Magic - 3rd to final paragraph.
"The Infernal Might of a demon may be manipulated with the Art of Vim. Demons may be attacked with Perdo Vim spells such as Demon's Eternal Oblivion (or it's non-Hermetic equivalents) in either form, assuming the target has been sensed. The Infernal Might of the demon is reduced by a successful casting of the spell, and the demon also loses any Might Pool points that exceed its reduced Infernal Might. As the demon's Infernal Might is reduced, subsequent Perdo Vim spells penetrate more easily and have greater effect. The Demon's body is actually eroded using these magics, and a demon that is reduced to an Infernal Might of zero is destroyed, leaving behind no corpse (and thus no vis). Demons in either spiritual or physical form may be attacked with these spells and the result is the same".
It seemed kinda weird to me at first too, but it does make sense...
Strange, I thought Demons were simply banished to the Infernal realm, being indestructable.
And there's explicit mention of insubstantial vis being captured in RoP: Magic so I have no idea what it's talking about. Guess using apotropotaic magicks utterly destroy the Vis after all.
Well, it is explicitly possible to make immaterial things material, at which point you can just thump them with a sword. Magical attacks, by being magical, might also work on immaterial things - the trick is that immaterial is usually invisible so you have to sense them first.
There should, I suppose, be a MuTe(Me) or MuTe(Vi) spell to make something immaterial. It should also be possible to make a thing solid to both physical and nonphysical things, since enchanted swords which cut spirits are very traditional. This, I think, could be argued as MuTe(Vi) or CrVi, since you're either changing the sword or giving it a new, magical property. I'd lean towards the latter, I think, but require a requisite.
Enchanting the sword does have the odd effect that it needs to penetrate, so you can have a sword which passes harmlessly through some things and not others.
As far as the Apotropotaic killing and vis goes, here is my interpretation. After all, if a beast expends its Might trying to kill you, it still has the full Vis quota in the corpse. I can understand how a demon might just be banished if so slain, since Demons are effectively souls and so unable to be destroyed by Hermetic magic, just inconvenienced. Ghosts and other spirits, however, should be destroyable, leaving their tattered remains which a canny magus can harvest.
I believe It has been said (sorry, still no citations, could have been on the forum...) that a "destroyed" demon is reduced to the status of permanent resident of Hell. They are no longer "demons", but merely like any other damned soul. So I would say it is more than mere inconvenience.
And they are then likely punished for their failures.
Spirits I can see being destroyed, but I thought Ghosts were explicitly eternal? Says so in the PeMe spell. Indeed, it seems to suggest that spirits are only apparently destroyed (according to some philosophers.)
Yes, but it doesn't say they are apparently not destroyed.
It looks like ghosts are destroyed by PeMe.
But, this is inconsistent with how some philosophers in Mythic Europe think the world works. If these philosophers are right, then the ghosts can't be destoryed, it only looks like they are. However if these people are wrong, then the ghosts are destoryed. The available evidence (that fact that the ghosts appear to be destroyed) suggests these philosophers are wrong.
Of course, destruction by PeFo spells is, as noted in the beginning of the magic chapter, often inconsistent.
Mind you, if this is all true, it makes creatures with Mights 0-5 actually EASIER for magi to kill than it is to kill mundanes. Despite (or, rather, because of) having a direct tie to the Magic Realm, they become more vulnerable!
I mean, sure, there are ways to quickly disable large numbers of mundanes, but they're at least several magnitudes above a level 3 might smasher. Or level 5 if you want to slaughter them on masse.
I s'pose the threat of losing Vis is one thing, but a magus is going to go ahead and choose his life over Vis, and being able to wipe out a giant with a Non-fatigued spontaneous spell is rather silly. As we were doing it before, sure, you've deprived it of all its Might until it can recover the Score, but it can still take its club and smash you in the head and go home, same with magical animals and so on. Nowadays, it's easy.
Supernatural characters need to be getting up into the Might 15-30 range before they are a significant problem to most magi.
Not all magi are optimised for killing critters of course. Magi can cripple themselves by having moral issues about killing things, by spending their time studying something other than PeVi, by being stupid, etc.
You don't need to be optimized in PeVi to kill Might 0-5 creatures. You can be an apprentice with 0 in each art and just not botch the roll, effectively (though for 3-5, a high roll would be needed for just that pinch of Penetration needed, assuming you aren't shouting your Latin, exaggerating your gestures, or lacking in Stamina.)
Now, simply failing to attack, that'd work.
In any case, this does emphasize the Cardinal Rules of Ars Magica Magical Combat: Avoid detection, strike first.
By all means, not the focus of any good Saga, but it does come up.
If you are casting spontaneously, you need a casting total (including die and stamina) of around 20, to kill a Might 5 creature (with a level 5 DoE type-PeVi) spell).
20 / 2 = 10 = level 5 effect + 5 Penetration.
Maybe you need slightly less than 20, if you have a decent Penetration Score. Maybe you need slightly more if you are standing in an awkward aura (one that boosts the critter's magic resistance, and reduces your penetration).
Of course, if you have learned the formulaic version of the spell it's easier...you only need a casting total of around 10 to nuke a Might 5 critter. But then you are a magus that is beginning to become optimised in PeVi --- you have dedicated a season to inventing a spell (although admitedly, you can probably invent several low level PeVi spells in a season).
Other doubt, in the main descriptions about Beasts of Virtue say that they can't have the Flaw Monstrosity, but immediatly the Boar have it.
Too there aren't others two Flaws: susceptible to privation nor Pagan, when it's said that the two are in the Flaws and Virtues sections.
I think thats it's need make some qdditions for include aclarations for familiar and experiences and the rules for daimons apprentship in Mysteryes, like ther are additions about the magic.
I think this is one of those topics that was built by the designers to be unanswered (and potentially unanswerable). I seem to remember that according to RAW (I think in the Criamon section in MC), those who die with the proper Divine rituals are gone from a Hermetic standpoint... they can't be summoned, talked to, etc. From a rules perspective, that could be called "destroyed", I suppose, but you could get burned at the stake for suggesting it in character.
I seem to remember that magi in Twilight are similarly unavailable to Hermetic interaction (though RoP: M gives us a bit more data there). Does that count as "temporarily destroyed"?
Whether a ghost that is "destroyed" via PeMe or is sent to its corresponding realm is mostly irrelevant from a gameplay standpoint, I'd argue; they are beyond the reach of Hermetic Magic. From the perspective of a SG, having a character with a theory that magic-aligned spirits who are PeMe out of existence are actually just banished to the Realm of Magic, and could be communicated with from inside the realm would make all sorts of a wonderful story, whether or not I as SG decide to rule the player correct or not in their belief.