Blood Harvest

You summon a polearm of Umbral energy to strike down at your foes. As you slam down your umbral polearm, all creatures in a 15-foot line from you makes a Dexterity saving throw, taking 2d8 Necrotic damage on a failed save or half as much damage on a successful one.

Creatures with the Bloodied condition take an additional 1d8 Necrotic damage.

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