(Slinger's) Nimbus Bullet

You use the sling bullet used in the spell’s casting and make a ranged attack with it from a sling against one creature within 60 feet of you. On a hit, the target suffers the weapon attack’s normal effects and then becomes sheathed in Tempestuous energy until the start of your next turn. If the target willingly moves 5 feet or more before then, the target takes 1d4 thunder damage, and the spell ends.

This spell’s damage increases when you reach certain levels. At 5th level, the Ranged attack deals an extra 1 lightning damage to the target on a hit, and the damage the target takes for moving increases to 2d4 thunder. Both damage rolls increase by 1d4 at 11th level (1d4 and 3d4) and again at 17th level (2d4 and 4d4).

{optional detail: "With a crack of the sling the imbued bullet wizzes forward with Tempestuous energy, followed by a thin trail of blueish-white lightning."}