Black lightning

You spend one action charging your hand that crackles with a  wicked black lightning, you make a melee spell attack against one target and the attack deals 3d8 lightning damage to the target.

Additionally, This spell ignores lightning immunity: while only dealing half dmg to lightning immunity, dealing full dmg to lightning resistance and x2 to no resistance.

When you cast this spell at higher levels, the damage increases by 1d8