Dark Oblivion

Your hand is engulfed in green, shadowy energy as you close it, causing a void pool with 10ft. radius to appear beneath the creatures within range. Spectral hands emerge from the void, grasping at the affected creatures and slowing their movements. Each creature in the area must make a Dexterity saving throw. On a failed save, a creature takes 2d8 necrotic damage and its movement speed is reduced by 15 feet until the start of its next turn. On a successful save, a creature takes half damage and isn't slowed.