Incorporeal Movement. The Villi can move through other creatures and objects as if they were difficult terrain. It takes 5 (1d10) force damage if it ends its turn inside an object.

Call of the Grave. The Villi uses its magical power to cause skeletal hands to erupt from the earth and pull a large or smaller target within sight (30 ft. range) down into the earth.

The target must succeed on a dc15 strength saving throw. On a failed save the target is grappled and is pulled down into the earth at the rate of 1 foot per round. In the initial round, if the target has not been pulled into the earth, on a successful save the target is unaffected by this ability and is resistant to any further uses of this ability by the Villi.

If the target fails the initial saving throw and is pulled down into the earth, the target is allowed to repeat the saving throw at the end of its subsequent turns and halt its descent into the earth. The target can then climb, as an action, unassisted, one foot out of the earth per turn. With help, the target can, as an action, climb two feet out of the earth per turn.

If the target is pulled completely down into the earth, the target is restrained and begins to suffocate. 

Dance of Death. The Villi invites a living creatures within 5 feet of it to begin the dance of death. The target must succeed on a DC 15 Charisma saving throw or begin to dance with the Villi. At the beginning of the target's next round, they gain one level of exhaustion. If the target gains six levels of exhaustion, they die. The target may attempt the saving throw again at the end of its turn, ending the dance of death with a success, and gaining immunity to the dance of death for 24 hours. 

Hypnotic Dance. When a Villi begins to dance, the movement is so beautiful that any creatures that are looking in its direction risk being hypnotized. Any creature watching a Villi dance must succeed on a DC 16 Wis save or risk being hypnotized for 1d4 rounds. With a successful save, a creature is immune to the Villi's hypnotic dance for 24 hours.