A Magical Wolf has the power called "A Pack of One".
How would you convert that statistically to the rules using Realms of Power: Magic?
Ritual Power, Creo Animal (Vim) base 50, Range Personal (0) or Voice (+1)?,
Duration Diameter (+1) or Until (Opponent brought down) (+4)?,
Target Group (5 Wolves, although Group target would be able to create many more wolves) (+2)?
How do you handle the wolf only dies if all copies dies?
Can a Magus invent a Creo Corpus version of this for himself or others, or to instill this effect in other familiars?
CrAn seems possible, in which case I believe it'd be a base 15, not 50. One might be able to make a case for it being MuAn though, as description clearly indicates the effect is really creating one-wolf-with-many-bodies rather than a group of separate-but-identical-wolves. What the guideline for "creating an extra body" would be, I'm not sure. I'd probably start with a base 25 "radically change an animal in an unnatural way". Range would definitely be Personal in that case. Target would be Individual, I believe, as you are casting it on the one "starter wolf", although the multiple bodies created seem to me to call out for a bump of +1 or +2 magnitudes to the final level. I think the Duration would have to be a non-Hermetic Special. Something like Until fits in many ways but is over-powered for the relatively short duration that a single hunt or combat would normally last, and Diameter is much too hard-coded for the effect as described. Maybe another +2 magnitudes?
All that would put it at level 45, which seems OK at first glance. A Greater Power quality would give you such a thing with a Might Cost of 4, so you'd have to throw in something from Improved Powers or some such to get the cost down to the stated 2. Since the given Init is +10 and the default from a Greater Power would give -3 with the wolf's +2 Qik, you'd also have to seriously invest in pumping that up as well. Improved Powers x 3 would let you put 13 points towards the Init and, coincidentally, give you the 2 more needed to tweak the cost, so that seems to work out well.
With MuAn, I'd accept the health effect as a positive side effect and not bump up the level any further, although by the same token, I'd definitely accept any one wolf body or portion thereof as being an appropriate Arcane Connection to all the rest, and possibly even saying a Me effect cast on one could conceivably touch the others as well as the effect states "the pack is really one creature". If multiple minds are actually being created, and I don't think they are, I think you'd have to throw in Cr and Me requisites and maybe bump things up another magnitude for the separate effect. At that point, perhaps it'd be better to toss Mu and go back to CrAn for something more like a cloning spell than a splitting one.
As far as recreating such an effect using Hermetic magic, I'd say this particular one, especially given its non-standard Duration, would not be directly repeatable as-is without a Breakthrough of some sort. A different version that had a standard duration seems more likely but, as always, I think that'd be a judgement call for the individual storyguide to make while keeping their troupe in mind. At worst, I think it might require a Minor Breakthrough to produce something like this.
With regards to the Me portion of your idea, remember that An covers both a beasts body AND their mind, so it would not be a requirement to have Me as a requisite.
That would be quite true if it were a normal wolf but, in this case, the creature in question has Intelligence instead of Cunning, so Me would apply if it were decided a mental component was needed at all.
According to A&A, changes in Quantity are always under the purview of Muto which creates some problems in this particular instance since the player and SG must negotiate how dramatic a change they consider the spell to be and thus the final level will likely vary somewhat from troupe to troupe.
I initially considered using the "change an animal into a different animal" guideline with a Target of 'Group' as below, but that proved rather unsatisfying as well as mechanically problematic as illustrated below. In retrospect, a base of 15 or 25 might be more appropriate as a single wolf splitting into 5 parts can hardly be considered a natural act even if the net result is fairly normal, albeit magically aligned, wolves since the supernatural change instituted could be deemed one of Quantity.
Pack of One
(Muto/Animal, Level 25)
Range: Touch. Duration: Special. Target: Group.
This spell uses the hermetic guideline to "change an animal into a different animal", in conjunction with a Group target, to transform the targetted wolf into a pack of wolves each possessing the same stats as its 'parent'.
(Base 5, +1 Touch, +1 Special, +2 Group)
The problem with using the above spell to mimic the power on page 193 of ArM5 is that by default this spell, a written, generates a pack of approximately 50 wolves. I'd recommend, therefore, that the magic wolf not be constrained from discrete changes in quantity, thus allowing us to do away with the Group target and thus reducing the number of wolves to a lean five and the effect's Level to 15. With the target reduced to Individual, there's no real reason not to change the Range to Personal, but if Level 10 seems too low (as it should) I'd seriously consider adding a magnitude or two of complexity to represent the high degree of coordination implied in the power's desciption.
The effect is, in any event, quite sophisticated and if it is even possible for hermetic magi would likely require a magnitude or two in any appropriate requisites (Mentem, as mentioned above, or perhaps Rego) or even just a result of the complexity inherent in the effect!
I would say it would need, Muto (your changing the body) Rego (so they can act as a team, you pick which injuries are kept etc.), Corpus (to change the body) Mentum (to change the mind), group (to get a group of targets), Touch (because the people are separating) and at least one magnitude for fancy effect. That means +2 magnitudes for reqs. +2 for groups. +1 touch. Also +1 or more for fancy effect. That's +6 right off the bat. Then we'll want an a duration, probably equivalent to sun if we want to mimic the effect. I don't have my book with me, but the base is going to be pretty high probably at least 15.
So we get: Army of One
Muto Corpus 55+
(Mentum, Rego req)
Duration: Special Range: Touch Target: Group, Ritual
This splits the magi into five identical copies, and this lasts until a specific target is destroyed, the magi stop working towards that goal or a month which ever is less. These magi may act as a group with leadership five. The vanguard is always the least injured one. Upon combining all fatigue levels are combined. If each magi has lost five fatigue levels the recombined magi has lost 25. Fatigue recovery is 1/5th of the normal rate. The total warping gained for the recombined magi is the total of all magi, as is time spent under active magical effects. The wounds are of the least injured magi. They magi may act as they have leadership five. The magi gain XP as one unit and may mentally communicate. They may not perform lab work as that would end the spell, or may one of the magi be "kept in reserve" or similar.
Base 15+ 2 reqs+2 group+2 special+1 fancy+1 touch
Note: Increasing the group size is not easy due to the requirements to keep the magi working together and synched up. For every five added magi double the magnitude for the fancy effect. Failure to do so may cause death and insanity. (This is a game balance to prevent lab work abuse.)
Its a pretty cool attack spell. But its vis expensive. I think its fair. You could make a moon or year duration spell for lab work, but it would cost a ton of vis, and cause warping.
I'm still lacking A&A but it really has to be the next book I get. Way too much of particular interest to me to delay it further!
I'd argue against Group in any case, as the effect targets one subject. I don't think the fact it converts that individual to a group changes the target level. I'd cite the difference between the Mu-based Hornet's Fire (one fire to many little flying fireballs) which has T: Ind and Clouds of Thunderous Might (many clouds to one storm) which is T: Group.
Are there any suitable examples of a one-to-many effect in A&A? As I say, I don't quite have that one yet.
According to the spell index (Apprentices May 2012), the only Muto spells are on p33 (2 MuMe). There's a 3rd one on the same page, but I did not see any spell around the metaphysics section where they discuss quantity and other categories.
No. In fact, the matter is only really addressed for a paragraph or so in the 'Philosophiae' chapter where there's a section on how the Hermetic arts interact with Aristotle's theory of Form, Matter, and Subject. Basically, changes in Quantity can be either continuous (growth/shrinking) or discrete (changing the number of targets). The closest it comes to providing a way to duplicate matter is a hypothetical spell to make two coins from one - which the book recommends Group for, but hints that this might constitute a flaw in Bonisagus' theory.
Phony Edit: Actually, my rereading of the section would seem to suggest that changes in discrete quantity may well be outside the purview of Hermetic Theory though obviously this wouldn't hinder the wolf...
Since Ritual Powers allow you to break Hermetic Limits, as per the RoP:M, I think this version, for the magical wolf, would need to be a Ritual power. Good thing you have 20 points to spend on Qualities, to get the cost down from using it. It would need at least 2 major qualities to get the required levels, if it is MuAn of 45. Several points on Improved Powers would be necessary for cost and initiative. Being allowed to break Hermetic Limits with the Ritual might help with overcoming some of the problems describing it.
I would make the effect Cr(Re)An 50:
Base 15 (create a mammal)
+1 Rego (to control the created creatures)
+2 R:Voice (control can be exerted at howling range)
+2 D:Special (+2 magnitudes seems the closest duration for an effect lasting for the duration of a "task" ranging from a few minutes to many hours, see e.g. Wind at the Back; though it could be argued that Duration should be Conc, reducing the final level to 45)
+2 Group
This does not cover the fact that only the least wounded duplicate remains -- which is arguably a bonus -- but since such an effect could create many more wolves, allowing the original staying "out of the fight" and get no wounds, I'd say it's balanced.