Lightning based blaster build?

[sithlordnergal]

EDIT: I just checked, the Scribe Wizard cannot have lightning-damage-substitution spells using a 9th level spell slot.

And they can only have lightning substitution spells using a 8th level spell slot if the DM allows Illusory Dragon as an "all damage type" spell in the spellbook, even if the text is explicit you choose the dragon's damage type on casting.

So that's between one and two whole spell levels the Sorcerer Blaster has access to, while the Scribe Wizard Blaster hasn't.

Eh? What are you talking about? Scribe Wizards have a way to turn spells into lightning damage very easily at 9th level. The wording for their ability is "When you cast a wizard spell with a spell slot, you can temporarily replace its damage type with a type that appears in another spell in your spellbook, which magically alters the spell's formula for this casting only."

So you have to have a spell that has the required damage type. Prismatic Wall is a 9th level spell that deals Fire, Acid, Lightning, Poison, and Cold damage, that satisfies the requirement for Scribe Wizards. Its kind of like how Storm Sphere grants Lightning or Bludgeoning damage. I will admit, the Scribe Wizard does lack thunder damage at high levels. But that's not a major issue.