Source: Arcana Unleashed
Level 5 Necromancy (Cleric, Warlock, Wizard)
Casting Time: Action
Range: 120 feet
Components: V, S, M (a handful of grave dirt)
Duration: Concentration, up to 1 minute
Skeletal hands burst from an area on the ground within range. The area consists of up to four 10-foot squares, which you arrange as you like. Each square must be contiguous with at least one other square. That area is Difficult Terrain for your enemies.
Any enemy in that area when the skeletal hands appear makes a Strength saving throw. On a failed save, a creature takes 6d6 Necrotic damage, and until the end of its next turn, the creature subtracts 1d6 from all its damage rolls. An enemy also makes this save if it enters the area or ends its turn there. A creature makes this save only once per turn.
Using a Higher-Level Spell Slot. The damage increases by 1d6 for each spell slot level above 5.