I have always felt that a bolt of lightning striking from out of the heavens would be more intimidating than one jumping from your hand to the target. The former carries a suggestion of Divine wrath.
If there is already a storm underway, then I imagine that it would be a Rego Auram effect.
Also, if there is not already a storm, then the above effect would follow a casting of Clouds of Rain & Thunder or of Clouds of Thunderous Might. But could these be combined into a single Spell? I have an image of my magus raising his staff up (either to create a storm or just connect to a pre-existing one) and then slamming it down on the ground, resulting in a bolt of lightning blasting down out of the heavens to strike his Target. Very dramaticā¦ and very destructive.
Two separate Spells, depending on whether or not there is already a storm? Or one Spell that can be applied in both circumstances. Rego Auram (with a Creo requisite, if needed?)
You could use CrAu or ReAu for both forming a lightning storm (Clouds of Thunderous Might and Gathering of the Stormy Might) and calling lightning from a storm cloud. CrAu would create a storm or bolt, while ReAu would redirect clouds into a storm or a bolt forming.
A variation of The Incantation of Lighting is possible for directing a bolt of lightning from storm clouds. It would still be Base 5, require Sight range, and not need the +4 Unnatural modifier. So only level 20, but it would only work outside and if there was a storm. With +1 Unnatural it would work outside as long as there was clouds.
Going at it with ReAu, you need to add duration to it or perfectly time your casting with a lightning bolt. Lightning is a āVery Severeā weather phenomenon, so Base 5. Requires Range Sight so +3. Concentration for +1. Group to affect the whole thing for +2. So ReAu level 35, that lets you direct lightning strikes from a storm as they form for as long as you concentrate.
The spell description in the book are all thematic. One can make a spell of the same level and change the cosmetic elements. For example, a pilum effect be a sudden blast of fire appears on the person, a comet from the heavens, a dragons head manifest in front of the target and breathes fire.
A magi could adjust Incantation of lightning such that the lightning comes from the heavens. It could manifest itās own small cloud it comes from if the spell creator wished.
I already touched on it, but CrAu spells specifically require an Unnatural modifier for their creation location/condition. For them it is not just thematic but part of the formula.
Creating Lightning from a storm cloud? Completely natural
Creating Lighting from a cloud? +1
Creating Lightning from clear sky? +2
Creating Lighting indoors or from casters hands? +4
Iāve answered the bolt from heavens but the Rego aspect is interesting. Does controlling a thunderstorm mean the magi can direct a lightning bolt, or just the clouds? Would the magi need a lightning strike to start, then direct it. If I was the story guide and the player chose to make the spell, Iād allow the magi to control the cloud to make the bolt.
Level 20
Bring Forth the Wrath of the Darkened Sky
R: sight, D: mom T: ind
From an existing storm cloud you draw forth a lightning bolt to hit a target, doing +30 damage.
(base 5, +3 sight)
Iāve gone with sight, not voice, mostly because even though it would require two spells or a stormy day, a level 15 spell doing +30 damage is extreme. My justification, a storm is large and chaotic, finding the condition for the lightning bolt in a 50 pace radius is unreliable, so it has to be sight.
Edit: A later post makes me realise this is an overthink. It has to be sight as the cloud to Rego the lightning is the target, not that which is hit by the lightning. This is basically a sling of vilano flinging a lightning bolt instead of a stone.
Sight range is pretty much a requirement for weather control spells, unless you want to fly up to the clouds. With Voice range you could not reach the clouds (and forming lightning) from the ground, so you would have to hope a strike was happening within range that you could redirect when the spell went off.
You could control every aspect of a thunder storm except the lightning with the āSevereā Base. The only aspect that bumps it up to āVery Severeā is the lightning. That higher Base is needed to control lightning bolts and creating lightning is naturally something thunderstorms do, so I agree with you that a spell designed to trigger the creation of lightning in a thunderstorm is perfectly acceptable with the āVery Severeā Base.
One thing of importance to note, this is not a Creo attack spell making the material on the target. You are redirecting the lightning from a cloud that is several miles away from where you want it to strike. So Finesse rolls are required.
Your example spell is identical to how I would write up a single bolt ReAu version. My example was just for being able to redirect multiple bolts from the storm while concentrating.
The Re attack spell theme has always been finesse, no resistance. Often the attack could not get too high, as thereās only so damaging a thing one can āflingā. This is a good way to get some rather extreme rego damage out. One would near a fair bit of finesse to make it worthwhile though.
Thatās not necessarily true - Wielding the Invisible Sling (ReTe 10) is an autohit spell to fling a rock which needs to penetrate, whereas Invisible Sling of Vilano is an initial impetus spell which uses finesse and doesnāt need to penetrate (when the object is not otherwise subject to resistance).
I don't think lightning has a quality that can be aimed and this bypass MR. I would require it to be directed by Rego. The nature of lightning being unpredictableā¦
So ReAu20 Bring Forth the Wrath of the Darkened Sky is directing ānaturalā lightning from a ānaturalā (i.e. per-existing) storm and doesnāt have to penetrate Magic Resistance, but if the storm had been conjured with, say, CrAu 25 Clouds of Rain and Thunder the storm itself and any resulting lightning would be magical and so have to penetrate MR?
BTW, lightning being shot from ones hand is clearly āUnnaturalā, but lightning from a storm cloud would be expected, itās just the directing of it that would be āUnnaturalā. But how much? After all, people DO get hit by lightning.
To an extent, the āunnaturalā magnitude increases are there for play balance, and I don't think there are official rules on how unnatural any phenomenon is. You just need a feel for whether the final spell level is reasonable. In this case, youāre getting the same damage as Incantation of Lightning with a much lower spell, but I think the āyou need a storm firstā opportunity cost justifies it.
Even if you do use CrAu to conjure a storm, and the bolts are resisted, you are still getting much better Penetration than IoL. Again, I think that's justified by the extra spell youāve learnt and spent time casting, and the āonly outdoorsā restriction.