Electric Discharge

Powerful electric current begins to build up within yourself. For the duration, you take 1d4+1 lightning damage at the start of each of your turns. As a bonus action on your turn, you can end the spell. When you do this, you unleash a massive blast of lightning.

When you do this, all creatures in a 100 foot line that is 5 feet wide emanating from yourself must make a dexterity saving throw. A creature takes an amount of lightning damage equal to 9d6 plus an additional 2d6 for every round that passed before you unleashed the lightning on a failed save, or half as much on a successful one.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the base damage increases increases by 1d6.