Doom Blade

A blast from the void forming a line 50 feet long and 5 feet side erupts from your hand. Each creature in the line must make a Dexterity saving throw. A creature takes 4d6 necrotic damage on a failed save, or half as much damage on a successful one.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d6 for each slot level above 2nd.