Undertakers Grasp

When cast undead hands appear in a 20ft sphere grasping at the creatures within it. Any creature hit by this must make a wisdom saving throw or take 4D8 necrotic damage maximum roll on a failed save. On a success take rolled damage. 

In addition creatures who fail the save have disadvantage on attack rolls while in the area of effect but when successful are immune to the effect.

Creatures who enter the area and creatures who start their turn in the area take 2D8 necrotic damage and the area is considered difficult terrain.

The area of effect does not spread around corners

At higher levels. when you cast this spell using a spell slot of 4th level or higher, the damage increases by 1D8 for each slot above 3rd