Would that work? The spell says "You can tell whether an image has been created or altered" if the image has been destroyed what's Discern Images of Truth and Falsehood acting upon?
In any case, I'm doing something different for Andreva, the spell's written up I'll post it in a bit.
AFAICS Hermetic invisibility magic does not just destroy iconic species, but replace them with others which still provide an image: only a specific image, like the magus turned invisible, is destroyed, while the image of the room he is in is just altered.
So a standard (ArM5 p.144) Discern the Images of Truth and Falsehood of level 25+ should detect a standard PeVi 20 (ArM5 p.146) Veil of Invisibility.
I didn't read the 25 pages of this thread. So please forgive me interfering on just a technicality.
Cheers
I followed your link. I've always taken it that the image is he thing that blocked Iconic species thus if you destroy the image the spell needs to do nothing more in order to achieve invisibility. It needn't "also pass others along in their stead". Is this just YMMV or is ther some text to support your view that I'm not taking into account. (ISTR there was something in A&A that bothered me about species but I don't remember what it was).
As far as I see it, a primary purpose of this thread is to bring up technicalities to be messed with. Given a choice I'm always going to try and write the spell in the weird edge case. Your comment is anything but interference, its kinda the point.
Andreva’s Creo Terram lab total for inventing spells is 84 so it takes in one season she’ll invent this
The Creo Terram guidelines say “Creating earth in an elaborate shape or with some unnatural property is one level of magnitude higher than the listed guidelines.” I think that the +1 magnitude for complex shape I have in the level calculation is all that is needed.
I thought about target individual for this because it is one cloud and it creates less than one individual sized amount of terram. Group on the other hand is defined as “The spell can affect a group of people or things. The components of the group must be close together in space, and the group itself must be separated from any other things of the same type.” Which also fits.
Is it target individual, is this spell really level 5 not 15?
She also has lab total enough left to invent wall of protecting stone (or a more cool target group version if rain of dust is really individual).
That's all of the time that she has. hopefully I 'll get some feedback on the stuff from the last few pages before I tie everything up for 76-90. (for now I'm going to closely read the invisible assassin characters in Sub Rosa 17 and see what they thought of that I didn't.)
I assume, that I do not need to argue, that Imaginem magic affects species as described in HoH:S p.61ff, not the far more general Aristotelian species. Based on this I give you my argument, which tries to do with very few rules quotes and applies very basic optics explaining shadows, well known to ancient and medieval geometers and scholars, without explicit authority from the rules.
By the description of the invisibility spells on ArM5 p.146, even an object no longer emitting iconic species still blocks light and casts shadows.
We have also:
So light carrying iconic species from behind an object cannot continue through that object, invisible or not. Then just what puts the iconic species from behind the invisible object onto light beams towards the viewer, if not the invisibility magic proper?
And these iconic species carried from behind the invisible object now change the image of the room around the invisible object.
Cheers
Yup that's the thing which I hated. I remember now.
So going from the books it looks like invisibility has to be messing with species directly not just destroying images.
Now my revised model of an invisibility spell functions by both destroying the image and shuttling all of the iconic species across the volume of the invisible object where light can't carry them. I still don't necessarily have an image that Discern the Images of Truth and Falsehood's function of "tell whether an image has been created or altered" can act upon.
Is there an issue with my revised model? Or have we taken it back to YMMV (even if were really look hard at the texts and try to come up with an answer rather than thinking about what's best for our table)?
AFAICS not. Its my model, too.
But iconic species moved across the invisible object are magically created and/or altered. And hence show up under Discern the Images of Truth and Falsehood of sufficient level, just like ArM5 p.146 Illusion of the Shifted Image does.
Cheers
Ok having now looked at Ragna and Octavianus, the intangible assassin characters from Sub Rosa. I can see some of what they did differently than Andreva. Much of the differences are driven by the fact that their goals were to kill their opponent, wizard's war or not, while Andreva's goal was to survive a wizard's war. Also Andreva didn't have her virtues selected to optimize her assassin-ness but there aren't really any set of virtues comparable to having 60 years as a maga under your belt before turning yourself towards a particular goal. She has more power which informed her choices.
First of all they saw that Fading Star of Evening was already a spell written up and they didn't recreate the same spell and call it Touch of Twilight 
Second she knows but one arcane tunnel spell and that one at level 40!. Andreva learned the Arcane tunnel spell early in her career when the entire covenant could get together and wizard's communion an attack on a dragon. Andreva probably couldn't convince Bausas that an attack upon another magi was just and she might not be able to get too many others to help her either. If her target has mastered a tunnel spell for defense then she's probably out of luck.
On the other hand Stab Across Europe is unlikely to be the sort of thing any target who isn't confraternity of Roland has prepared for.
While Andreva has tried to collect defenses against the ways that she is likely to be attacked she has holes in her protection. She isn't protected from acid, she isn't protected from aging. This was to be expected but I think I underestimated how many ways there are to attack a maga that are really straight forward, not requiring clever plans.
It turns out that Andreva already had a lot of applicable virtues and skills -Flawless formulaic magic, high finesse and craft magic to make representations, and some skills with both, school of ramius and school of vilano combat.
She has some tools to gain Arcane connections these include -60 years of contacts, some decent investigation spells, and the two effects that she's enchanted into her talisman, but she doesn't have the sort of plan that Ragna had.
But the biggest surprise is that there is a guideline for art specific rego vim suppression spells in HoH: Socitates! I'm going to have to go back and rewrite her Postpone the Assassination enchantment on the last page.
Ah yes, those two. I believe both Christian and I are at least passingly familiar with those.
Right tool for the right job sort of situation.
And you might want to review 'similar spell' to make sure your magic resistance mastery works. 
Probably not, no. That would be a very hard sell indeed.
Very true!
I like aging as a weapon, but it's a lot harder to use than it was back in the 3rd edition when I first went over the idea.
Enjoy!
The core book says "Same effect, at a different Range, Duration, or Target. All three may differ." I was tempted to say an arcane tunnel is an arcane tunnel regardless of size. Is your take different?
That's my prefered take, but I'm pleased that others agree.
Oh, I think I see what prompted your suggestion that I check the similar spells rules. I had wondered why you asked.
Andreva's casting total in a +3 aura with words, gestures and a confidence point is only 36. If she somehow got a X 10 multiplier on penetration score through a fixed AC and lots of sympathetic connection work (that she might be able to do with enough work, she certainly has the tools to pull it off) she might get a 50 penetration with her present spell but an 80 penetration with a level 10 spell. These 30 points could make the difference if the target had prepped by learning spell defense on tunnels (but would be irrelevant if she could gather friends to do wizard's communion - But friends who know wizard's communion is a questionable proposition).
I didn't go that way for a few reasons:
*First, I don't think it would make her a better NPC.
*Second, vim isn't really one of her strengths, yet even without putting in the work on vim, with spell defense mastery her parma is 100 versus arcane tunnel spells. Others in her "weight class" might reasonably have similar defenses, and
*Third, it's her main goal to live through the experience and intimidate others into leaving her apprentice alone, she's not really into killing her opponent unless that's the only way to ensure she or her people don't die and there won't be more wizard's wars.
*Fourth, and most importantly, she doesn't have any seasons left. She spent them doing other stuff
So I'm going to sum up 76-90 but I'm still really eager to get feedback on the spells and enchantments.
Andreva would have wanted to spend this period creating sculptures that move the observer to awe, pathos, and joy. She would have liked to have created underground grottos so beautiful that they bring observers to tears, she would have liked to have spent time with the retired grogs fencing, drinking wine, flirting, and reciting poetry. Instead she spent it as a genderswapped Mad Eye Moody screaming "constant vigilance" over and over to her apprentice, (who stayed on for two extra years just for their protection).
It could make sense for her to die in a wizard's war here, she's done a great deal to make herself more safe and more dangerous but that's no guarantee. Of course that means I can't present you with a functional NPC, a detailed write up of a corpse isn't a great game aid.
One option that I've been thinking of is to give her a really tragic story.
Her apprentice passes his(?) gauntlet and at the next full moon gets a wizard's war declaration, Andreva has been vigilant about doing recon and collecting arcane connections so she is able to present the aggressor with a wizard's war declaration of her own within five minutes.
The defenses of the magi prove adequate to prevent arcane tunnel assassination. But the recently gauntleted young magus gets captured. His captor uses intellego mentem to determine that the apprentice, in fact, has no knowledge of the Confraternity of Roland initiations. the Verditious keeps his prisoner secured and goes to find Andreva to attempt to come to an understanding and prevent any deaths.
the Verditious finds Andreva who, believing that he has murdered her former apprentice slays him forthwith before the poor fellow has a chance to speak. By killing her attacker, she sets off several watching ward and waiting spells including spells that kill the imprisoned former apprentice. The Confraternity of Roland magus had set these "safeguards" up to ensure that Andreva didn't try to kill him for fear of the consequences, and that would have worked, if only he'd found a way to get that information to Andreva earlier.
Between reading letters that weren't delivered in time and repeated castings of whispers through the black gate everything becomes clear. Andreva is devastated. It doesn't even really end her issues with the Confraternity of Roland because while they now have evidence that she doesn't know their initiation, they also know for a fact that she murdered one of their members when he was seeking to make peace with her.
Of course a story of triumph with a happily ever after ending would work here as well.
My plans for the next period, (which I can't help myself making even if it is unlikely that I'll ever flesh them out). Are to create enchanted sculptures that act out scenes for their observers, create
a series of caverns that represent the epitome of beauty and comfort; filled with aquam and ignem leser enchantments to make them impressive. She'll also spend a lot of time in study, I think she's done a lot of lab work the past few periods and she'd be well served by taking a little less intense schedule.
For her aging roll the first year she has -11 from her ritual, -2 from her bronze cord -2 from her living conditions and -1 from her lab for the first year at 102 years old so 1 year at -5
then she gets the new longevity ritual at -29 so she gets 8 years at -23
and then 6 years at -22.
She'll end at 116 years old and take one year of apparent aging so she now looks 44
With Andreva's time with her apprentice and the lab periods when she didn't need Grace's help, Grace has 16 seasons unaccounted for. I'll say she spent 4 with the apprentice and I'll give her another 60 xp for the remaining 12. Here's how she'll spend it
Teaching 2 (apprentices) for 15
Magic lore to 3 for 15
Infernal lore to 3 for 15
Faerie lore to 3 for 15
Talk about going out with a bang!
Upon reflection, I probably dropped off the board for a year and a half in order to avoid maiking this character sheet, a million little numbers, enough to drive one mad
Here is Grace
Here are the unique spells, I'll try and get the enchanted devices up soon
Animal Spells
Aquam Spells
Auram Spells
Corpus Spells
Herbam Spells
Ignem Spells
Mentem Spells
Creo Terram Spells
Intelego Terram Spells
Muto Terram Spells
Rego Terram Spells
Vim Spells
Here are the enchanted devices. Andreva is finished through 90 years (although I may do another post collecting all of the sponts that I wrote up in the last 26 pages, no promises). I'll just add that I'm pretty pleased with how she turned out all things considered.
The following five enchanted devices (through the Wand of Titanic Sandcastles) were created for use on the Covenant’s ship.
I did not include the statue of Peter and Patricia that she created for Bausas
and thinking more about a next period, Andreva might be a good fit for The Knights of the Green Stone. It would be interesting to have a wealthy ~120 year old maga in the role of the new initiate, because power changes personal dynamics even when it shouldn't.
If I did that, I'd need to deal with the fact that the knights teach free expression which she already has, magical memory which might be the weakest virtue in fifth edition, and vulgar alchemy which has messy rules that don't work as they should.