Electromancer

Your innate magic manifests in lightning. You are your lightning, and your lightning is you.

Electric heart

At 1st level, whenever you start casting a spell of 1st level or higher that deals lightning damage, lightning magic bursts from you. This burst causes creatures of your choice that you can see within 10 feet of you to take lightning damage equal to half your sorcerer level (minimum of 1).

When you cast a spell that deals a type of damage from the following list, you can change that damage type to lightning or thunder: acid, cold, fire, lightning, thunder.

Lightning in the veins

At 6th level, you gain resistance to lightning damage. In addition, spells you cast ignore resistance to lightning damage.

Electromancers fury

Starting at 14th level, when you are hit by a melee attack, you can use your reaction to deal lightning damage to the attacker. The damage equals your sorcerer level, and ignores resistance to lightning damage.

Electric soul

At 18th level, you gain immunity to lightning damage. In addition, any spell or effect you create ignores resistance to lightning damage and treats immunity to lightning damage as resistance to lightning damage.