As two actions, a sphere of thunderous clouds springs into existence centered on a point within 20 meters. The sphere remains for the duration. A creature that enters the spell’s area for the first time on a turn or starts its turn there must make a Fortitude saving throw.
On a failure, it takes 1d8 concussion damage and is deafened until the end of its next turn.
On a critical failure, it takes twice as much damage.
On a success, it takes half as much damage.
On a critical success, it takes no damage.
At the start of each of your turns if the clouds are within 20 meters of you, you can cause them to move up to 2 meters in a direction that you choose. If you spend an action, you can move them up to 10 meters.
Until the spell ends, you can use an action on each of your turns to cause a bolt of lightning to leap from the center of the sphere toward a creature you choose within 10 meters of the center. Make a ranged spell attack against the target, which you have advantage on if the creature is in the sphere.
On a hit, it takes 2d8 lightning damage and can’t take reactions until the end of its next turn.
On a critical hit, it takes twice as much damage.
On a miss by 4 or less, it takes half as much damage.
Creatures within 5 meters of the sphere have disadvantage on Perception checks made to listen.
You can increase the concussion damage by 1d8 and the lightning damage by 1d8 for every two additional mana expended.