*EDIT* - Ok, sorry this is a lvl5 Divine Druid spell. I've realized this in a later post, and suggested something different.
I beleive we should have the Call Lightning Storm spell as an arcane spell available to Wizards/Sorcerers. It's part of the Half-Elf Dragonmark and available through the addictive Stormreaver Coockies. This spell reminds me of the Thunder Storm spell from Diablo 2. The only thing I think they should change about the spell is the addition of a graphic, a staticly charged halo above the casters head.
Here's what the cookie says:
Call Lightning Storm
Target: Self
Durration: 1 minute 9 seconds
Spell Resistance: No
Creates a stormcloud that persists for some time and randomly strikes nearby enemies with bolts of lightning for 5 to 50 electrical damage. A successful Reflex save reduces the damage by half.
D&D Dice: Deals 5d10 electrical damage.
Caster Level: 15
I'm pretty sure it discharges a lightning bolt every 5-10 seconds, although I haven't tested it to be sure.
*Edit* - Just tested the cookie in Kobold Assault, waited for a big mob of kobolds, the spell procs every 2-5 seconds.
I think this can be easily translated into a useable spell. Make it a lvl7 spell, it does 1d10/3 caster levels(max 6d10 at lvl18), and the duration is 5sec/caster level(able to be extended). So at lvl13 when you get the spell it lasts 65 seconds(2min10sec extended), and does 4d10 electric damage per hit.
New spell version:
Call Lightning Storm
School: Evocation
Level: Sorcerer/Wizard 7
Components: V, S, M (Powdered Ruby)
Metamagic: Empower, Eschew Materials, Extend, Heighten, Maximize, Quicken
Range: 30 ft.
Target: Self
Durration: 5 seconds/caster level
Saving Throw: Reflex save takes half damage
Spell Resistance: No
Creates a stormcloud that persists for some time and randomly strikes nearby enemies with bolts of lightning for 1 to 10 electrical damage per 3 caster levels. A successful Reflex save reduces the damage by half.
D&D Dice: Deals 1d10 electrical damage every 3 caster levels (max 6d10 at level18).
With Empower/Maximize/Extend on at level 20 it has the potential of becoming 15-150 damage per hit over 3 minutes and 20 seconds. That's not including enhancements or item/potion boosts to damage or crit chance. (I'm hoping I got the math right there...hehe)
I personally think this could be very viable as an electric alternative to Wall of Fire. Its not as easy to control as Wall of Fire as far as how/when its going to deal damage, which is a downside, but think about it you're calling forth a lightning storm to strike at you enemies. Lightning isn't very predictable, although it should be more attracted to monsters wearing heavy armor. It has similar damage output, but more random, and because of its random nature it lasts longer.
Let me know what you think.
~Nim