Chthonic magic taints the user's magic as if the user had the False Gift. I'm not talking about the "extra bonuses" that make it clearly infernal, just the "basic" chthonic magic that e.g. allows no penalty from infernal auras. What's not clear to me is whether the magus who has learned Chthonic magic has the option of not accessing it (e.g. casting spells while accepting infernal aura penalties) and, as a consequence, exhibiting no taint, or if learning Chthonic Magic permanently and irrevocably "stains" the Gift. I would be inclined towards the former interpretation, by analogy with Holy Magic: the magus who has learned Holy Magic cannot use it to sin, but can still use his "old" Hermetic magic to sin.
On the other hand, sensing the taint takes an angel or arch mage if you are lucky.
Consdiering that sense holy/unholy seems to require penetrating magic resistance: it is easy to block. Even parma of 1 means that normal diff 15 goes up to 20 for penetrating. Since this seems to be InVi type sensing effect: Someone with high vim to use in the arts would would have parma + vim that is very high.
n the Light of andorra saga, Only infernal lore in recognizing the geotic arts in use really has a chance since the infernalist there has 20 vim and 3 parma requiring 35 penetration over the base diff 15. Good luck in getting an ABILITY roll over 50.
Yup. Which makes making enchanted devices and the like a good way to get caught. However, I'm not sure Sense Holy/Unholy can be used on traces. I'm not even sure it can be used on active spells. I'll have to go read the rules. I know it can be used on objects and individuals.
Yes, but InVi cannot tell the difference between Infernal and tainted. And Demons can lie to InVi. The point is that it becomes difficult to know for sure.
Yup. I wouldn't be doing it myself without quaesitorial backing or if I'm really, really sure and know I will be able to make a strong case at Tribunal.
Depends what the target of the InVi is. It is perfectly legal to look at the target of a spell if it's a patch of neutral ground or a miscellaneous villager or something like that.
So you can't just stumble across and unconsciously notice unholiness - if you have the sense holiness/unholiness virtue but don't actively go looking for evil? I don't buy that, though it might be the RAW. Mythically, I think of it as a sixth sense, and you don't usually need to turn your sixth sense on.
I'd treat it just as an awareness ability... and live with the aggravation it causes mages to be "pinged" by an effect when that person is nearby.
Your saga might vary, of course
(Yes, I realize that could be a troublesome ruling in your case, being a maga of the order and all. Perhaps you could consciously suppress it, though?)
Chthonic magic makes the character's magic always look Infernal to Divine & Infernal detection, but it looks normal to Magic and Faerie. Only using the special RDT or the dark feats bonus makes it register as Infernal to Magic and Faerie. You are not able not to use Chthonic Magic's basic features (and the accompanying taint) since it automatically modifies your Gift, just like Faerie Magic. Holy Magic works differently because two different ways of casting (holy and vanilla Hermetic) are involved, which is not the case here. Faerie and Chthonic just give an additional secondary alignment to the Gift and Hermetic magic.
Therefore, if you never use the special tricks you are safe in the Order since having a Tainted Power or Gift is legal and SH&UH is no evidence of wrongdoing (it cannot distinguish between taint and real infernal nature). You shall reap enimity from Divine-aligned beings, but who cares, it's unlikely they are going to get miracles to support them in that circumstance, it's effectively the equivalent of having an occasional Supernatural Nuisance (Divine).
Using the special bonus is tricky since it exposes you to Hermetic discovery, it's effectively the equivalent of a (temporary) Dark Secret. It is only reasonably safe if only you use it on short-lasting (Mom, Diam, or Sun) spells, or away from your sanctum or covenant, or you use normal MuVi or PeVi spells to erase their traces or hide you sigil. Never use it on permanent or long-lasting spells that give away your sigil.
For this purpose, Spirit Summoning works just like having un-boosted Chthonic Magic, while Ablating, Binding, and Commanding work just like using the "wicked" bonus of CM. I would discourage the use of Ablating on different grounds, Commanding is reasonably safe to use as long as you only use it on magic and faerie spirits and observe the same precautions that you ought to use for CM casting bonus, Binding is only reasonably safe to use on yourself to bind a magic or faerie spirit for antiagathic purposes, where any long-lasting traces are going to be covered by your MR (but the environmental traces still need to be covered). Using Binding on everyting else is far too dangerous IMO.
The other tricky issue may be that by Initiating Chthonic Magic or Spirit Summoning you can truthfully tell that you never knowingly sought Infernal powers, which is not true anymore if you Initiate Binding or Commanding. It is also true, however, that if you find yourself in a situation where you are going to be subject to a truth-reading or mind-reading, notwithstanding the prohibition against scrying, you must have left around so much damning evidence of Infernal traces that your case is already very compromised anyway.
Hmm, you say this as if it was without doubt and without need of justification [EDIT: Ok, you later edited it as I was posting:)]. I have two objections:
First, as already stated, why not have it act like Holy Magic - so that you can still use "plain" Hermetic Magic even if you know Holy magic?
Second, who says that Faerie Magic "automatically modifies your Gift"? Even for Faerie Magic you have the option of not using it when it causes you disadvantages (see e.g. HoH:MCp.88): you may substitute it for Magic Theory and to increase the amount of vis you can use, and intheseconditions (only) it adds to the number of botch dice you roll.
So far three people are for automatic taint (Ovarwa, MarkoMakoto and Wanderer) and two against it (myself and Exarkun)
Because Holy Magic comes with a different, Divine-aligned way of using magic, and therefore it gives you the option of using either that or vanilla Hermetic magic. Chthonic and Faerie do not, they make Hermetic magic automatically aligned with their respective realm through no action or choice of the mage (or better, it is done when the Virtue is gained, during Initiation or apprenticeship, although conceivably you can be born with that kind of Gift). They are essentially like Gentle or Blatant Gift in nature.
This is something different, an additional separate perk that you may choose to use or not. Even if you do not, however, your Gift is still modified so that automatically you reap full benefit from Faerie auras, you are not warped by them, and they give you no additional botch dice. Likewise, Chthonic gives you the choice of substitutiing MT or not, but you still gain full benefit and no drawback from Infernal auras automatically. Auras alignment is something that happens automatically, either you have it or not, and the taint comes with it.
Again, however, as long as you stick to CM's basic features, the taint is no big deal. It is not going to give a magus serious troubles in the Order, since they realize that it can be gained for wholly different reasons than being an diabolist, and as I see it, the Dominion is an enemy of mages just like the Infernal. If you want to have the kind of magus character that is buddies with the Divine ( ), then CM would be inappropriate anyway, the Tyrant Upstairs has a wholly unreasonable policy about using the weapons of the enemy against them.
You are safe in the Order until you are noticed by a magus who also has Sense Holiness/Unholiness, or until some magus' companion with that Virtue notices you, or until you botch while doing something the SG considers mean and nasty, and he decides that the botch effect is that your Tainted magic is noticeable.....
Technically, it is even Hermetically legal to use the special tricks. The Code forbids trafficking with demons, not smelling like one.
Not necessarily so, in either direction. Manufactured Ignorance lets a magus be ignorant of all kinds of things. A magus might easily understand the nature of his Cthonic Magic or Summoning.
The botch would be nasty, especially if you are unaware of its effects. S H/U is no big deal, as long as you left around no other evidence that registers as Infernal to Hermetic investigation. It is well known that S H/U is no reliable evidence of diabolism since it registers a lot of stuff as Infernal which is proven not so to extensive Hermetic investigation, again and again.
This may be a reasonable interpretation, but then by the same meter, Binding and Commanding magic and faerie spirits ought to be legal too, despite RoP:I tells that having Infernal Powers is illegal.
Manufactured Ignorance would make a magus with Infernal powers register as innocent to truth-reading and mind-reading, sure, even if powered by the Divine. OTOH, unless a magus finds tainted powers objectionable on moral grounds (pussy ), they are surely legal in the Order.