Bolgavis's Burning Bands

The wizard pulls forth bands from the Elemental Plane of Fire which race toward the target. 

The wizard makes a ranged spell attack against a target up to huge size. If successful, the target takes 3d6 fire damage and must succeed on a Strength saving throw or be restrained for 1 minute. While restrained by the bands, the target takes 3d6 fire damage at the start of each of its turns. The target can repeat the saving throw at the end of each of its turns, breaking the bands on a success.

 When you cast this spell using a spell slot of 3rd level or higher, you can target one additional creature for each slot level above 2nd