OK, this time the spell is yer basic creo ignem fiery death spell. The only difference being instead of conjuring the fire on a target (ala Pilum of Fire) this spell allows the caster to spew flames from his mouth like a dragon.
My rationales, touch range since the area of effect starts at the magus' mouth. Size +2 allows for a area of effect of 100 square paces (base is 1, +1 is 10 square paces and +2 is 100 square paces) With a cone effect at 45 degrees, that gives us a range of more or less 20 paces.
Fiery Breath of the Drake
R: Touch, D: Mom, T: Ind
With a great exhalation, the caster breathes out a great gout of flame covering a cone with a 45 degree angle. The cone extends 20 paces and anyone in the effect takes +15 damage.
(Base 10, +1 touch, +2 size)
OK, working without books as i'm in a car park...
Base 10 does +15 damage in a natural shape, or +10 in an unnatural shape, ala AoFR.
Touch is fine, as that is the near end of the fan.
Range calc seems fine, but would actually specify that the spread is xx paces also.
(I think xx is either 15 or 20 paces, but my math brain broke.)
Other than the damage being high, I'd say it looks fine (subject to book checks).
For Pilum of Fire the Range is Voice, because it's functionally equivalent to creating an Individual sized fire directly at Range Voice. That's also the reason why you don't get a level modifier for the weird shape. The fact that it starts at the caster or look like a javelin is merely cosmetic.
If it "really" started at the caster, it would either a) initially encompass the Target, too, which would generally entail a size modifier for a big fire and/or for a weirdly shaped one or b) initially not encompass the Target, in which case it would need being moved there and a Rego requisite. Incidentally, as gerg notes, you run the risk of burning yourself with Touch range spells, so you'd need to either throw in a Rego requisite, trust your own Parma, or take some other measure to protect yourself.
For Arc of Fiery Ribbons, it's almost the same thing, except that you can burn a Group rather than an Individual. Note that this is a legacy spell, so it really does not conform 100% to the guidelines (its area potential is slightly more than a Group of Individuals).
Crystal Dart is different. The Dart is created close to the caster, but the control on it (the Rego requisite) extends all the way to the target, so one has to pay for the Voice Range (but the spell need not be aimed). One could imagine an aimed version like the Invisible Sling of Vilano (from HoH:S) where the initial impetus is imparted at Touch Range, and the dart is then allowed to fly "on its own" to the target -- this would be only Touch Range, and one magnitude lower.
Yep. ISoV is effectively an aimed variant of WtIS. The range increment is IIRC 20yards. I haven't managed to find a way to increase that by the RAW.
(An entertaining thing to note is that spell range in that case is range to target rock/equivalent, not range to victim. Thus a sight range spell can fire a rock from sight range with a range increment of 20y. This does lead to the entertaining idea of cobblestones jumping down an alleyway out of sight to hit a target that you cant see, the spell having been cast from the mountaintop...)
I always seem to need to add background to the character when I post these spell topics.
This particular spell is being created by a character who is descended from a dragon. All part of some crazy and really quite bizarre breeding experiment. As such he has quite a good line in dragony spells (change forearms and hands to claws, grow wings, a variety of fiery breath spells, etc). He also has the major virtue Immunity: Fire, making him immunity to the damage from creating fire at touch range.
I did look at Arc of fiery ribbons but as Ezzolino said, its a legacy spell and doesn't really fit into the guidelines so well. Its also a group spell.