Billibus' Boneyard

Conjured bones erupt from the ground in a 30-foot cone starting from you in a direction of your choice. Each creature in that area must make a Dexterity saving throw, taking 6d6 necrotic damage on a failed save, or half as much damage on a successful one.

The bones make the ground difficult terrain for the duration.

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