If you wanted to try to do this without gouging your eyes out with laggy weapon swaps, you really want Call Lightning Storm. Which means you have two realistic choices: Half-Elf Sorc/WM or Cold Druid/Blightcaster. Certainly not a fix or a caster pass, as you really have limited options if you wanted to max out this idea.
1. Two maxed-out jewels
2. Lamordia Weapon 1 - Revel + Lightning Lash + Alchemical Acid,
3. Lamordia Weapon 2 - Revel + Bitter Frostbite OR Lingering Acid Burn
4. Lamordia Weapon 3 - Revel + Rippling Energy
5. Clank OR Wither (Blightcaster) - Rupturing Echo OR Grip of Venom, Ash
Now getting gear for all of this is tough; you need Force, Cold, Lightning, Alignment, Sonic (maybe), Acid (maybe), Poison (maybe). I doubt it is possible to max them all out; you would start with your main spell elements and fit in what you can.
I would get two mantles, Draconic and Primal. Cold Druid doesn't have sonic spells, which is a problem.
We want to cast Call Lightning Storm:
Swap:
2. Lamordia Weapon 1 - Revel + Lightning Lash + Alchemical Acid,
3. Lamordia Weapon 3 - Revel + Rippling Energy
Mantle = Draconic
You could also swap in items (Lightning/Force Lore + Critical Damage etc.)
Call Lightning Storm
Mantle = Primal
Swap:
4. Clank OR Wither (Blightcaster) - Rupturing Echo, Ash
3. Lamordia Weapon 2 - Revel + Bitter Frostbite OR Lingering Acid Burn
Procs:
Revel
Lightning Lash
Alchemical Acid
Rippling Energy
Draconic Mantle
Primal Mantle
Rupturing Echo or Grip of Venom
Bitter Frostbite or Lingering Acid Burn
The exact swaps are going to differ between Druid (Primary spell DPS is Cold/Force), Sorc (Cold/Lightning), Blightcaster (Acid/Force). You also lack a 2nd LGS debuff, without more swaps.
I personally would not mess with Dripping from Red Dragon armor. There are a lot of fire immunes and things that heal from fire, and you don't want to have to swap that out. You also cannot fit all these elements in anyway.
Cold Druid cannot easily proc the sonic portion of Primal mantle (assuming you would not go Fatesinger), so you do lose some DPS with that option compared to Blightcaster/Wildmage/Sorcerer. It does have some other advantages.
There might be cases where you would be better off using Ooze somehow in your swaps versus an additional dot.
Immunities are still an issue; most viable options can only strip one element, so many of these procs might be negated at various times. You could also be healing mobs in various cases.