The Hand of Loros

A blast of lightning erupts from your hands. Each creature in a 30-foot cone must make a Constitution saving throw. On a failed save, a creature takes 3d8 lightning damage and is hindered by the fierce storm, reducing its movement to 0 for its next turn. On a successful save, a creature takes half damage and isn't hindered.

A creature that is wet (on a failed save)has its movement reduced to 0 for 1 minute, or until it or another creature uses an action to free it from the hindered condition. 

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d8 for each slot level above 2nd.