thunderclap and flash

You dash past (no opportunity attack) and hit a creature with a melee weapon attack, the weapon flashes with static as you strike. The attack deals an extra 2d6 lightning damage to the target, and 1d4 lightning to creatures in the surrounding 5 ft line , which become visible if  invisible, and the main target sheds dim light in a 5-foot radius and can’t become invisible until the spell ends.  

At Higher Levels. When you cast this spell using a spell slot of 1rd level or higher, the extra damage increases by 1d6 for each slot level above cantrip.