Wyrmkrow (Oni/Night Hag Hybrid)

Frightful Presence: Each creature of Wyrmkrow's choice that is within 120 ft. of the Dragon and aware of him must succeed on a DC 19 Wisdom saving throw or become Frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, Ending the Effect on itself on a success. If a creature's saving throw is successful or the Effect ends for it, the creature is immune to Wyrmkrow Frightful Presence for the next 24 hours.

Innate Spellcasting. Wyrmkrow's innate spellcasting ability is Charisma (spell save DC 14, +6 to hit with spell attacks). He can innately cast the following spells, requiring no material components:

At will: darkness, detect magic, [Tooltip Not Found]

1/day each: charm person, cone of cold, [Tooltip Not Found]

2/day each: plane shift (self only), ray of enfeeblement, sleep

Magic Resistance. Wyrmkrow has advantage on saving throws against spells and other magical effects.

Magic Weapons. Wyrmkrow's weapon attacks are magical.
Regeneration. Wyrmkrow regains 10 hit points at the start of his turn if he has at least 1 hit point.

 Spellcasting. Wyrmkrow is an 11th-level spellcaster. His spellcasting ability is Charisma (+10 to hit with spell attacks, spell save DC 18). He has the following spells prepared, which he can cast without material components:

1st level (4 slots): identify, ray of sickness

2nd level (3 slots): hold person, locate object

3rd level (3 slots): bestow curse, counterspell, lightning bolt

4th level (3 slots): phantasmal killer, polymorph

5th level (2 slots): contact other plane, dream, scrying 

6th level (1 slot): eyebite

Multiattack. Wyrmkrow makes two attacks. 

Glaive (Large Form). Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: (2d10 + 4) slashing damage.

Glaive (Small or Medium Form). Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: (1d10 + 4) slashing damage.

Claws.(True Form Only). Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) slashing damage.

Change Shape. Wyrmkrow magically polymorphs into a Small or Medium humanoid, into a Large giant, or back into its true form. Other than his size, his statistics are the same in each form. The only equipment that is transformed is its glaive, which shrinks so that it can be wielded in humanoid form. If Wyrmkrow dies, it reverts to his true form, and his glaive reverts to its normal size.

Etherealness. Wyrmkrow magically enters the Ethereal Plane from the Material Plane, or vice versa. To do so, he must have a heartstone in his possession.

Nightmare Haunting (1/Day). While on the Ethereal Plane, Wyrmkrow magically touches a sleeping humanoid on the Material Plane. A protection from evil and good spell cast on the target prevents this contact, as does a magic circle. As long as contact persists, the target has dreadful visions. If these visions last for at least 1 hour, the target gains no benefit from its rest, and its hit point maximum is reduced by 5 (1d10). If this effect reduces the target's hit point maximum to 0, the target dies, and if the target was evil, its soul is trapped in Wyrmkrow's soul bag. The reduction to the target's hit point maximum lasts until removed by the greater restoration spell or similar magic.