Telepathic Bond. The fiend ignores the range restriction on its telepathy when communicating with a creature it has charmed. The two don't even need to be on the same plane of existence.

Dark Guardian. When adula attacks a creature with a melee weapon they have disadvantage on attacks against any creature other than her until the end of her next turn. In addition if they deal damage to a target other than adula that creature gains resistance to the damage.

Shield Lord. Adula has a dark aegis that protects her from damage. Adula has 20 temporary hit points that deplete when adula takes damage. Whenever a creature starts their turn within 5ft of her or hits her with a melee attack they take 10 necrotic damage. At the start of her turn the shield regains 20 temporary hit points.

Lesser Magic Immunity. Adula cannot be affected or detected by spells of 6th level or lower unless she chooses to be. In addition has advantage on saving throws against spells and other magical effects.

Dark Infused Weapons. Adulas attacks are magical and deal an additional 27 (6d8) necrotic damage on hit. (Included in the attacks) 

Legendary resistance (3/day). If adula fails a saving throw she can expend a use of this ability to succeed instead. 

Inate Spell Casting. Adula has the following spells inately and can cast them without material components. Her spell casting ability is charisma with a spell DC of 25 and a +17 to hit with spell attacks.

At will: teleport, find greater steed, shadow of moil, guiding bolt (5th level), shield of faith, ray of sickness (7th level) 

3/day (each): destructive wave (necrotic), death ward

1/day (each): blade of disaster, invulnerability

Ginnungagap. Adula wields a magical staff called Ginnungagap. It has 13 charges and regains 1d12 + 1 charges at the end of a long rest. 20 is the DC for spells cast through the staff, and is based on the casters intelligence. She can expend charges from the staff to cast the following spells without requiring material components. magnify gravity (1 charge), pulse wave (3 charges), gravity sinkhole (4 charges), gravity fissure (6 charges), Dark star (8 charges), ravenous void (9 charges).

multiattack. Adula makes two attacks with calamity when she takes the attack action or casts a spell and makes one attack.

Calamity. Melee Weapon Attack: +15 to hit, reach 10 ft., one target. Hit: 21 (2d12 + 8) force damage and an additional 27 (6d8) necrotic damage. This weapon deals three times damage on critical hits. 

Charm. One humanoid the fiend can see within 30 feet of it must succeed on a DC 23 Wisdom saving throw or be magically charmed for 1 day. The charmed target obeys the fiend's verbal or telepathic commands. If the target suffers any harm or receives a suicidal command, it can repeat the saving throw, ending the effect on a success. If the target successfully saves against the effect, or if the effect on it ends, the target is immune to this fiend's Charm for the next 24 hours.

The fiend can have only one target charmed at a time. If it charms another, the effect on the previous target ends.

Draining Kiss. The fiend kisses a creature charmed by it or a willing creature. The target must make a DC 23 Constitution saving throw against this magic, taking 62 (10d10 + 9) psychic damage on a failed save, or half as much damage on a successful one. The target's hit point maximum is reduced by an amount equal to the damage taken. This reduction lasts until the target finishes a long rest. The target dies if this effect reduces its hit point maximum to 0.

Etherealness. The fiend magically enters the Ethereal Plane from the Material Plane, or vice versa.

Parry. Adula raises her AC by 7 when hit by an attack possibly causing it to miss.

Deflect Missiles. When adula is hit by a ranged attack she can use her reaction to reduce the damage of the attack by 1d10 + 13. If this reduces the damage to 0 or less she can make a ranged attack using her strength modifier to throw the projectile back at the attacker as part of the reaction. 

Black Guard. Whenever a friendly creature within 30 ft of adula is hit by an attack she can use her reaction to switch places with the target accepting the blow meant for them. The damage dealt to her is reduced by half.

Adula has a pool of 3 legendary actions she can use at the end of a hostile creatures turn. She regains the charges at the start of her turn. 

Gaze of the Succubus. Adula targets a creature within 60 ft that she can see and peers into their soul. The target must make a DC 23 wisdom save on a failure the creature takes 21 (6d6) psychic damage and is stunned until the end of adulas next turn. They can attempt to free themselves at the end of their turn with a successful DC 23 wisdom save. If they succeed they take 10 (3d6) psychic damage.

Poison Aura. Adula emits a poison aura in a 30 ft radius centered on herself that lasts until the end of her next turn. Whenever a creature enters the aura the first time that turn or a creature begins its turn in the aura it must succeed on a DC 23 constitution save taking 27 (6d8) poison damage and becoming poisoned and they cannot regain hit points till the end of adulas next turn on a failure. If the creature is already poisoned they take an additional 18 (4d8) poison damage. On a success they take 13 (3d8) posion damage.

Cast a spell. Adula casts one of her at will spells.

Melee attack. Adula makes one weapon attack.