Andariel

Legendary Resistance (3/day). If Andariel fails a saving throw, she can choose to succeed instead.

Maiden of Anguish.  At the start of each turn, Andariel is healed for half of any damage she has dealt during the previous turn.

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

Seductive Form. Those who see Andariel and are within 30 ft. of her must make a DC 15 Wisdom saving throw. Those who fail to resist are overwhelmed by her otherworldly beauty and are at disadvantage on attack rolls, saving throws, and ability checks for the remainder of the round. On a success, they are immune to Andariel's seductive form for 1 minute.

Shapechanger. Andariel can use her action to polymorph into a Small or Medium humanoid, or back into her true form. Without wings, she loses her flying speed. Other than her size and speed, her statistics are the same in each form. Any equipment she is wearing or carrying isn't transformed. She reverts to its true form if she dies.

Magic Weapons. Andariel's attacks are magical.

Profane Beauty. Non-evil creatures who preform a melee attack or otherwise touches Andariel must preform a DC 20 Wisdom saving throw or take 15 (1d10 + 10) psychic damage.

Innate Spellcasting. Andariel's spellcasting ability is Charisma (Spell save DC 20). Andariel can innately cast the following spells, requiring no material components:

At will:
Vampiric Touch, Far Step, Telekinesis

1/day each:
Mind Blank, Synaptic Static

3/day each:
Modify Memory

Distracting Beauty. Andariel's otherworldly appearance distracts attackers, boosting AC.

Multiattack. Andariel makes three attacks: one with her whip, and two with her claws. She can then use her Draining Kiss.

Claw (Fiend Form Only). Melee Weapon Attack: +13 to hit, reach 5 ft., one target. Hit: 14 (2d6 + 7) slashing damage.

Heart-breaker (Chain Whip). Melee Weapon Attack:  +11 to hit, reach 15 ft., one target. Hit: 14 (2d8 + 5) slashing damage plus 7 (2d6) psychic damage.  If the target is hit, it is forced to make a DC 20 Constitution saving throw or become afflicted with agonizing pain. This pain functions as if the spell Power Word Pain was cast on the target, ignoring the hit points requirement, and creatures that are immune to being charmed are not immune to this effect.

Mass Charm. Three humanoids Andariel can see within 30 feet of her must succeed on a DC 20 Wisdom saving throw or be magically charmed for 1 day. The charmed targets obeys her verbal or telepathic commands. If the one of the targets 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 Andairel's Charm for the next 24 hours. Andariel can have only three targets charmed at a time. If she charms another, the effect on one previous target ends.

Draining Kiss. Andariel kisses a creature charmed by her or a willing creature. If the target is not willing, Andariel may attempt a grapple +5. The target must make a DC 20 Constitution saving throw against this magic, taking 54 (8d10 + 10) 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. Andariel magically enters the Ethereal Plane from the Material Plane, or vice versa.

Reflect Enchantment. When an enchantment spell targets Andariel and she succeeds the saving throw, the spell is reflected back upon the caster as if she had cast the spell herself (although she still uses the the original caster's spell save DC).

Andariel can take 3 legendary actions, choosing from the options below. Only one legendary action can be used at a time and only at the end of another creature's turn. Andariel regains spent legendary actions at the start of her turn.

Spell.  Andariel casts one of her spells.

Draining Kiss.  Andariel may attempt a grapple +5, if she succeeds in grappling then she lands a draining kiss.

Dominating Gaze (Costs 2 Actions).  Andariel can cast dominate person or dominate beast on a creature who is under the influence of her Seductive form.

Summon Succubi (Costs 3 Actions).  Andariel can automatically summon 1d4 +2 succubi.