Astellair's Static Crescendo

As an action you begin channeling electrical energy around yourself, creating a thin statically charged barrier that holds itself an inch away from your body.

The spell's base damage is 6d8. If at the end of your turn the spell hasn't ended, including the turn it was cast, the damage increases by 1d8.

You have resistance to lightning damage while you maintain concentration. In addition, any lightning damage mitigated by this spell is added to the spell's damage.

When you hit a creature with a Melee attack, you may choose to discharge the energy into the target. The Creature must make a Constitution saving throw. A creature takes Lightning damage equal to the accumulated damage on a failed save, or half as much damage on a successful one. After the creature takes this damage the spell ends.

However, If your concentration ends early then instead the energy is dispersed chaotically. You automatically cast the Thunderwave spell, with the thunder damage equal to the accumulated damage. As a result of the backlash, you are unable to move or take actions until after your next turn.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the base damage increases by 1d8 for each slot level above 3rd.