Ball Lightning

You hold out your hand and lightning springs from your fingertips, forming itself into a floating orb of of lightning. As a bonus action, you can move the orb up to 30 feet. When the spell ends, either because your concentration is broken or because you decide to end it, the orb explodes in a large blast of electricity that can move around corners. Each creature in a 15-foot-radius sphere centered on that point must make a Dexterity saving throw. A creature takes lightning damage equal to the total accumulated damage on a failed save and is stunned until the start of its next turn. On a successful save, a creature takes half as much damage and is not stunned. Objects and constructs receive twice as much damage from the blast.

The spell's base damage is 3d8. If at the end of your turn the orb has not yet detonated, the damage increases by 1d8.

If the orb is touched before the interval has expired, the creature touching it must make a Dexterity saving throw. On a failed save, the spell ends immediately, causing the orb to suddenly burst with a flash. On a successful save, the creature can send the orb to a location up to 40 feet away in a straight line. When it strikes a creature or a solid object, the orb explodes.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the base damage increases by 1d8 for each slot level above 5th.