Thread Tendrils

Weaving around in a 10-foot sphere centered on you, tendril-like threads of Strand lash out at those who would do you harm. When a hostile creature enters the spell’s area for the first time on a turn or starts its turn there, it must make a Dexterity saving throw. On a failed save, it takes 3d8 magical piercing damage, or half as much on a success.

Using a Higher-Level Spell Slot. The damage increases by 1d8 for each spell slot level above 2.