Bone Spikes

Channeling dark energy touch the ground summoning spikes made from bone in a 40ft cone, centered on yourself. The spikes deal 3d6 piercing damage, all creatures caught in the cone must make a DC 16 DEX check or take an additional 3d8 acid or necrotic damage, your choice which damage to apply.

At Higher Levels.  When you cast this spell using a spell slot of 3rd level or higher, you deal an additional d8 of acid or necrotic damage.