Another statistical oddity is 3 magi with a creo affinity. I think that this stuff just happens, deficient technique: Perdo was all over the place in Annulus Connectens but it isn't here anyplace.
IMO it's a matter of no concern.
The more I write the character the more I get interested in the challenges it might face - and start geeking out on the magical aspects. 
That said, I was intending to protect the Order and innocent. Templars well, let’s see how we agree to handle the seeds we decide to throw into the mix.
While the basic description of Momentary says, "but a moment," Momentary has been used in canon to handle up to 1 round or maybe a little more. That is how you can do MuVi on your own spell, though Fast Casting is clearly faster. Here are a few specific spells in canon:
Dust to Dust goes 2 rounds, though that could be argued to be style as opposed to anything that matters.
Curse of the Rotted Wood can go 2 rounds, and from the description it may matter as it may require up to 2 rounds to work.
Heat of the Searing Forge can last 3 rounds, at full for 1 round and then fading quickly.
I think it really comes down to your point about Momentary being enough for the effect. If the effect is quick, Momentary is enough for it to happen, whether that's a fraction of a second or a full round, or maybe even a touch more than a full round.
I hadn’t realized the Creo affinity repetition. I could easily change to a Perdo or Muto affinity. Let me check. In this case, there is no problem.
As for Flurry of Black Feathers I still think it works fine. Maybe “flurry” indicates the feathers billowing around by magic, but it’s just a huge pile of feathers.
A creation can appear at the magus’ hand and above ground. That may be unnatural but naturally the feathers fall to the ground. With the amount created there’ll be a fair bit of flurry since so light an object as a feather will drop to the ground more erratically than for example lead balls. And any amount of wind will affect them. Sure, in gale force wind the spell may not work as intended, but otherwise it should.
And if a huge pile of feathers appears instantly in the face of an attacker IMHO it should confuse or obscure sufficiently to function as a fast cast defence. D:Momentary may have varying examples of the specific time, but to last a full round is within the scope. And this should work for the intention for fast cast defence.
I’m already thinking about year 1-15. Corvus will invent the spells already discussed and more or less designed, and probably need some study to pull them off.
He will also spend time learning the locale (Area Lore) and language (Arab), Animal Ken as well as practice mundane animal handling and dealing with spies (Intrigue).
Salve sodales
I'd like to hear the oppinions of others about CrAn5 "Create a product made of animal materials (individual is a single hair, hide or tusk)"
How about camel dung? What is an individual's worth of dung? Is it a single, standard-sized pile of droppings? Or is the camel's dung instead a pile of many teeny-tiny pieces of whatever plants it ate, so I need T:Group to produce anything in quantity?
[Edit: Also, what is T:Ind for bees wax?]
I'm well on the way with Corvus' +15, and all the spells listed earlier - enabling a raven to take messages back and forth - are within Corvus' capabilities to invent in single seasons each with his Arts at Gauntlet. A few are beyond him, or take more time, but (if micromanaging) follow after years of study. I haven't assigned all 15 years but it's about half-half between study and lab.
That is a lot of lab work for the first 15 years. I have been checking possibilities, but whenever I consider increasing the lab work, I always end thinking that I should use the first 15 years of advancement to mainly study arts and get good totals for future lab work.
I suppose that your focus helps a lot.
Yes, the Focus does help. Most of the spells by far are only 3rd magnitude and could have been starter spells at Gauntlet. But it seemed more believable that spells for this narrow concept was developed by Corvus himself rather than invented and taught by the Parens.
But the higher level spells were too hard, but father throwing in some years of study they were within reach.
A “healthy” pile of dung seems reasonable, as that’s what I’d expect in common language. Like a donkey’s droppings (as they’re size 0).
For the wax is there a similar guideline in another Form you could crib from? I ask as beeswax seems like a substance which while natural isn’t really common unless cultivated. Is a pounds a reasonable amount to extract from a beehive in a single extraction? Too much?
I could also see a measuring cup worth as reasonable too.
I'm fiddling with some spells Corvus can use to help the covenant with, as well as other magi in their labs. Producing some goods which will be used up (Covenants calls these 'consumables' even though you don't eat them), seems a likely trick. Things burned to give heat or light don't need to last for very long. And since Corvus is an Animal specialist...But he is really hampered by the fact that it takes base 5 with animal to create just a single camel dropping, while Cr He base 1 can create a whole log. This is an uphill struggle, as the levels needed become enormous.
If Ind is a single dropping, then +2 magnitudes for group only gives 10. That's not a lot to burn, at hardly worth the effort of a Base 5, +1 Touch, +2 Sun, +2 Group device. Even though Corvus has an Animal score of 7+3 a gauntlet it does not take much study to get better results with Herbam, using the Base of only 1.
As for beeswax I'm turning away from that idea, since it would take too long to make the wax into candles. And producing finished candles is +1 mag for "treated animal product, like leather or cloth" - plus the wicks seems to be made form cotton, so the Herbam requisite ruins it.
I'm still thinking about producing oil from whales, fish, or seals to burn in oil lamps instead. What does one get from T_Ind here? I know it takes +1 mag for treated animal product, but will this get me "as much oil as could be produced naturally from a size +1 creature"? The seals known in ME are probably 60-150 kg, but I have no idea how much oil can be produced from their blubber.
Again, I'm sure a few seasons reading Ignem will more easily produce a flameless light 
Given the Base guidelines, it's usually easier to burn vegetable oil that wax, I think.
I realise that Corvus is an Animal specialist, but with a difference of four magnitudes, it might well still be the easier solution.
Not according to the box on sizes, p. 113 of the core book. That'll be a rather large pile of fecal matter.
Could you make flammable oil using Aquam perhaps? That might be practical.
Two seperate spells/effects. If you need a covenperson to turn the wax into candles, they're going to need the string as a seperate entity anyway? Or how about a piece of flammable animal bone/animal bone covered in flammable material?
...
You certainly could use CrAn for a few preservation devices. I wanted one for my lab but can’t get the lab total high enough to get it in one session.
As an alternative - Using Animal for the materials replacement device suits my Magus Arts too, what about going MuAn or ReAn instead of CrAn?
It’s MuAn base 3 to change one animal product into another, and it’s only ReAn Base 1 to manipulate animal products.
We’d need a few versions for each type of matter desired, and a few uses a day in an item. Refuse becomes oil, wax, etc.
Could be made to D: Moon and not be too much more expensive.
Rego Animal - is trickier, but could be used with a Creo Animal spell to age an animal to maturity and then to get materials and craft them with magic?
Geese might taste ok and they make quills, leather etc with rego crafting from all sorts of skins.
I’ve no real idea how much oil you’d get from a seal or whale but it is also a manufactured oil rather than a natural one. I think the fats need to be processed which I guess you could just Creo the end result or Rego the magically created fat?
From some of the history of oiling I think I remember the oiling stations being very easy to setup.
--I've given up trying to quote quoted quotes...
Yes, you're right - T:Group is a mass equivalent to 10 base individuals. So for Animal that is a size +1 animal, like a pony weighting maybe 100-150 kg. So that's a 1,5 ton pile of dung. I think that should take a while to burn. Still, it's a level 30 effect (Base 5, +1 Touch, +2 Sun, +2 Group)
Burning vegetable oil? I don't know if this was historically done. I'll admit my "research" has been wikipedia, but the oil lamp entry only lists animal or kerosene based oil, the latter ("mineral oil") was known in the Middle East.
Vegetable oil at this time, would that not just be olive oil, a valuable commodity? And that seems expensive to use for light, doesn't it? I don't think people in ME knew how to produce sunflower-, rapeseed, or other such oils.
If the wicks in the candles were created with wool rather than cotton it'd be purely Animal. HoH: Soc p 61 says Creo magic of things requiring no more then Finesse 9 (daily work of semi-skilled artist) does not even need a Finesse roll. But using Rego to craft things from raw materials will.
So still a base 5 will create a candle, with wick. Theoretically the candle can weigh up to 150 kg (Size +1 pony), however this would be useless since duration sun means this disappears way before it would have burnt down. T:Group would make 1500 kg of candles, that's easily several thousands of candles - more than enough for the covenant to use before the next sunrise or sunset. D:Moon would be better, so you wouldn't have to put up new candles and relight them twice per day, but that would make it a 7th magnitude effect.
However oil is covered by Aquam, by being a liquid. Creeping Oil is a canon spell which uses flammable oil. It uses base 3, even though the guidelines mention adding magnitudes for slightly or highly unnatural liquids. But I think the balance comes from the amount created, where those kinds of liquids are produced in much lower quantities compared to water. Said spell uses guideline for "creating liquid that is not contained e.g. on a surface". It's easier to create a liquid in a container, and harder to create it floating above someone's head.
Maybe I could use these guidelines as a framework, but base them on Animal instead? This would use base 2 to create a liquid in a container. Maybe +1 mag for slightly unnatural, like fruit juice. Or should it be +2 for highly unnatural? Neither fruit juice or whale oil occurs naturally by itself. Fruits need to be pressed, but I think the whale's blubber needs to be boiled to extract the oil. Sounds like +2, so that makes it base 4, just a little better than base 5 create animal product.
As for the amount, Aquam base Individual is "a pool 15 paces across and 2 paces deep at the center" for water. For ease in number crunching 1 pace = 1 m. I assume the pool has an average depth of 1 m then. Volume of a cylinder with diameter 15 m and height 1 m is roughly 3/4 x 15 x 1 = 11 m3 or 11.000 liters.
Base for natural liquid (fruit juice, olive oil) is 1/10 that, or for processed (like beer or wine) is 1/100 that. If whale oil is 'processed' that still gives 110 liters.
But looking at Creeping Oil and Footsteps of Slippery Oil (specifically non-flamable!) they both use Base 3 'create liquid that is not contained, like spread over a surface' and do NOT add magnitudes for being unnatural. Maybe this is a mistake, maybe this is "because legacy spell, that's why!"
By RAW a non-water liquid pays extra both by having a lower base amount and by adding magnitudes. Although the example spells do not.
...by now this discussion is purely academic, since I've given up on having Corvus create devices to do this. Most any other way to skin this cat is easier.
I'll try to come up with other Animal effects Corvus can develop. An effect to preserve animal matter T:Room is nice, but not very original. Janus did that as well. Spells to bring animals to maturity in a day likewise. Although quick growth of geese it good for both food and quills.
Corvus already has a healing spell, and following A&A different effects are needed to give recovery bonus to wounds and disease respectively. A version affecting didease would be quite helpful to the Templars...or rather their horses.
My quick wikipedia research says whale blubber was cut in thin slices and boiled. No mention of other processed needed.
Sperm whales were caught to get the spermacetti oil - or liquid wax rather - for an even cleaner and more expensive lamp oil. The head was cut off and the wax scooped out, it was only boiled to prevent it going rancid (not an issue for D: Sun). A single whale could have up to 1900 liters of oil.
So is that T:Ind? If so then Base 5, +1 Touch, +2 Sun is actually useful as well as doable. Although slightly impractical because of the need to fill up all oil lamps twice per day.
Why not make it duration Ring / Target Circle and remove the environmental trigger (and maybe one uses/day magnitude)?
No idea. I've read that the romans burned olive oil, but I can't really confirm my sources (or even remember what they were).
Mineral oil would be doable. CrAq, probably.
You're thinking like a northerner. In the mediterrean area, it's rather more easily available.
EDIT: Also, I suspect you can use a rather poorer quality of oil in lamps that what you'd normally use in cooking.
On one hand, wool burns rather poorly and so might not be a terribly good material for a wick. On the other hand, I have seen metal "wicks" - coated in flammable material - so meh.
It would smell horribly however.
As always, I'm not a fan of simply using a guideline from one Art with another, just because it would be 'neat' or 'useful'. At the very least, I would add a few magnitudes (since we'd be basically making a new guideline) - and so end up very close to that Base 5 anyway.
If it's an animal spell, it still uses the Animal definition of an "Individual". Ignore the Aquam target completely, unless you're using Aquam.
That's a good idea. Maybe we could use that in another afsnit!
Very true.
I think Tellus is right, don't mix guidelines, that's going to get messy.
Aquam seems to be the right Form to use for creating oil though, since it covers all liquids (those not inside bodies). Even though vegetable oil should fall under Herbam and fish oil should fall under Animal, Aquam is always used. IMHO flammable oil falls under: "Corrosive and otherwise dangerous liquids have a base Individual ten times smaller again, a puddle about a foot across and about six inches deep." If the depth of this is at the middle I assume an average of 3 inches deep. So that's about 17 liters of oil by my simplified calculations. That seems fair. Base 2 creates that in a bucket, Base 3 spread out on the floor, Base 4 in a huge. floating drop.
This seems easier, since figuring out what base Individual is for plant and animal products for fluids is (apparently) quite a bother.
I'm done assigning Corvus' seasons for +15 years and as soon as I've updated the character sheet I'll post the stat block as well as the spell designs.
Corvus spends his first 15 years (60 seasons) with:
8 seasons setting up and improving lab
16 seasons inventing spells*
36 seasons in study
*)I let Corvus invent his Moon Cycle of the Demanding Spell from a lab text. It contributes nothing to the project if he spend 6 seasons inventing it himself, or cramming ReVi for no other reason. Instead the time is spent developing new spells. I did throw in a season "wasted" to pay a service to someone for the lab text.
)
Looking at Aging I see he was lucky, and needs Longevity soon.