Avatar of Bolothamogg

Lashing Tendrils. 
Melee Weapon Attack: +5 to hit, reach 10 ft., one target. Hit: 22 (4d10) Force damage.
Target must make a DC 12 Athletics or Acrobatics check, on a fail they are grappled and the Avatar of Bolothamogg may make an additional Lashing Tendrils as a bonus action

2. Fear Itself. The targeted creature must succeed on a DC 18 Constitution saving throw or be paralyzed for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

3. Flee in Terror. The targeted creature must succeed on a DC 18 Wisdom saving throw or be frightened for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

4. Wave of Lethargy. The targeted creature must succeed on a DC 18 Dexterity saving throw. On a failed save, the target's speed is halved for 1 minute. In addition, the creature can't take reactions, and it can take either an action or a bonus action on its turn, not both. The creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

5. Call of the Void. The targeted creature must make a DC 18 Constitution saving throw, taking 36 (8d8) necrotic damage on a failed save, or half as much damage on a successful one.

6. Mind Over Matter. If the target is a creature, it must succeed on a DC 20 Strength saving throw or the Avatar of Bolothamogg moves it up to 30 feet in any direction. The creature is restrained by the the Power of Darkness until the start of the Avatar's next turn or until the Avatar is incapacitated.
If the target is an object weighing 300 pounds or less that isn't being worn or carried, it is moved up to 30 feet in any direction. The Avatar of Bolothamogg can also exert fine control on objects with this Power, such as manipulating a simple tool or opening a door or a container.

7. Dreams of Madness. The targeted creature must succeed on a DC 18 Wisdom saving throw or fall asleep and remain unconscious for 1 minute. The target awakens if it takes damage or another creature takes an action to wake it. This ray has no effect on constructs and undead.

8. Shadows Consume. The targeted creature must make a DC 18 Dexterity saving throw. On a failed save, the creature begins to turn be covered in a living shadow and is restrained. It must repeat the saving throw at the end of its next turn. On a success, the effect ends. On a failure, the creature is Petrified and Invisible until freed by the greater restoration spell or other magic.

9. All is Dust. If the target is a creature, it must succeed on a DC 18 Dexterity saving throw or take 45 (10d8) force damage. If this damage reduces the creature to 0 hit points, its body is reduced to a fine black dust.
If the target is a Large or smaller nonmagical object or creation of magical force, it is disintegrated without a saving throw. If the target is a Huge or larger object or creation of magical force, this ray disintegrates a 10-foot cube of it.

10. Sudden Death. The targeted creature must succeed on a DC 18 Dexterity saving throw or take 55 (10d10) necrotic damage. The target dies if the ray reduces it to 0 hit points.

Drift (Costs 1 Action). The Avatar of Bolothamogg may make a movement action without provoking opportunity attacks

Power of Darkness (Costs 1 Actions). The Avatar of Bolothamogg uses one random Power of Darkness.

Vanish into Nothing (Costs 2 Actions). The Avatar of Bolothamogg may cast Banishment; without needing Verbal, Somatic or Material Components.

Return to the Dark (Costs 3 Actions). The Avatar of Bolothamogg may Cast Plane Shift on itself; without needing Verbal, Somatic or Material Components.