Lightning based blaster build?

[Spacehamster]

So if wanting to build a lightningmancer, what classes, races etc would be best? Thinking something like Owlin 2 level tempest cleric, rest draconic sorcerer that chooses lightning damage, pick metamagic that transmutes elemental damage from say fire to lightning & then go to town with max damage fire/lightning balls?

Alternately 2 tempest 10 divine soul & start with tempest & go STR with heavy armor, then probably custom lineage for warcaster at lvl 1, fight in melee range & have spirit guardians as your concentration spell while blasting.