Homebrew
Maldrana casts one of the following spells, requiring no material components and using Charisma as the spellcasting ability (spell save DC 20)
Many of Maldrana's abilities impose the Judged condition, which is a condition unique to her. The Judged condition prevents a creature from regaining hit points. Additionally, a Judged creature takes 2 (1d4) psychic damage the first time it deals damage on a turn. The Judged condition can be removed by a spell or effect that causes the target to regain hit points, such as a fighter's Second Wind or consuming a potion of healing. If the Judged condition is removed by healing, the creature does not regain hit points from the triggering effect. The Judged condition can also be removed through an act of genuine reconciliation or heartfelt apology to an individual harmed by a transgression.
Hear Name. Maldrana hears her name when spoken, regardless of distance or planar boundaries. If a creature speaks her name three times in the same breath, Maldrana learns the creature’s name and precise location, and can perceive through the speaker's senses for the next 10 minutes (60 rounds) while remaining aware of her surroundings. Maldrana can choose to terminate this connection early. Once per day, Maldrana can manifest an Infernal Hex upon the creature whose senses she shares. The beneficial property of the Infernal Hex last 1d6+1 days, but the physical manifestation and detrimental properties last until dismissed by Maldrana or until removed by Remove Curse or similar magic.
Inscrutable. Maldrana is immune to any effect that would sense her emotions or read her thoughts, as well as any divination spell that she refuses. Wisdom (Insight) checks made to ascertain her intentions or sincerity have disadvantage.
Magic Resistance. Maldrana has advantage on saving throws against spells and other magical effects.
Magic Weapons. Maldrana's weapon attacks are magical.
Nightmare Fuel. Creatures that start their turn within 30 feet of Maldrana must succeed on a DC 20 Wisdom saving throw or be afflicted by hallucinations of nightmarish punishments for past transgressions. Affected creatures suffer a 1d4 penalty on attack rolls and ability checks until the start of their next turn.
Nightmare Resurrection. If Maldrana dies, her memory haunts the dreams of the creature that struck her down. At the end of each long rest, that creature must make a DC 20 Wisdom saving throw or Charisma saving throw (Maldrana's choice). The creature makes the saving throw with advantage if they are resting in a Hallowed area. On a failed saving throw, the creature does not receive the benefits of the Long Rest and gains a level of Exhaustion. A creature that dies of Exhaustion rises as a new vessel for Maldrana. She regains all her hit points and game statistics. The haunting can be removed by dispel evil and good, wish, or similar magic and a successful DC 20 spellcasting ability check.
(to hit +11, 177-194 dmg per round (including legendary actions and such). Save DC 20)
Multiattack. In her true form, Maldrana makes three attacks: one with her Nightmare Claw and two with her Chains of Judgment.
Chains of Judgment. Melee Weapon Attack: +11 to hit, reach 30 ft., one target. Hit: 18 (3d8 + 6) bludgeoning damage. If the target is Large or smaller, it is grappled and must succeed on a DC 20 Strength saving throw or be pulled up to 10 feet toward her. While grappled, the target is Judged.
Change Shape. Maldrana can use an action to magically polymorph into a Small, Medium, or Large humanoid, or back into her true form. Her statistics are the same in each form. Any equipment she is wearing or carrying isn't transformed. She reverts to her true form if she dies.
Nightmare Claw. Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit: 25 (3d12 + 6) slashing damage plus 14 (4d6) psychic damage.
Nightmare Touch (Recharge 5–6). Maldrana reaches into the mind of a creature she can see within 60 feet. The target must make a DC 20 Wisdom saving throw. On a failure, they take 66 (12d10) psychic damage, fall prone, and are unconscious until the end of their next turn. On a success, they take half damage and aren’t prone or unconscious.
Nightmare Haunting (1/Day). While on the Ethereal Plane, Maldrana magically touches a sleeping humanoid on another plane. A protection from evil and good spell cast on the target prevents this contact, as does a magic circle or hallow. As long as the 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 11 (2d10). 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 the hag's soul bag. The reduction to the target's hit point maximum lasts until removed by the greater restoration spell or similar magic.
Legendary Action Uses: 3. Immediately after another creature's turn, Maldrana can expend a use to take one of the following actions. Maldrana regains all expended uses at the start of each of her turns.
Phantasmal Conviction. Maldrana conjures a spectral chain to bind a creature that she can see within 60 feet of her. The creature must succeed on a DC 20 Dexterity saving throw or take 14 (4d6) force damage and be pushed or pulled up to 10 feet in any direction of Maldrana's choice. A creature that fails the saving throw is also Judged for the next minute.
Cast a Spell (Costs 2 Actions). Maldrana casts a spell.
Nightmare Apparition (Costs 2 Actions). Maldrana conjures an apparition drawn from the mind of a creature within 120 feet of her. This apparition is a physical manifestation of something that metaphorically imprisons them or holds them back. It appears in an unoccupied space of Maldrana's choice within 30 feet of her. Enemies of Maldrana that can see the apparition must succeed on a DC 20 Wisdom saving throw or be frightened of it until it vanishes at the end of Maldrana's next turn.
Nightmare of Guilt (Costs 2 Actions). Maldrana forces a creature within 60 feet to relive its sins. The target must succeed on a DC 20 Wisdom saving throw or take 27 (6d8) psychic damage and be stunned until the end of its next turn. The creature is Judged while it is stunned.
I Am the Scales (Costs 3 Actions). Maldrana emits a ripple of warped moral authority. Each enemy within 60 feet not behind total cover must make a DC 20 Charisma saving throw or become Judged for 1 minute.
Maldrana's Lair Actions are replaced by Villain Actions. Time-based Villain Actions take effect on initiative count 20 (losing initiative ties), but others take effect when their triggering condition is satisfied. These Villain actions are usable while Maldrana is in her Lair on Narakkas.
Round 1: Dig Deep. "Burrow deep into your conscience, dearie. I'm sure you'll find guilt." Maldrana burrows up to twice her Burrow speed into the earth.
Round 2: The Depths of Despair. "Do you feel that, dearie? That's the weight of your crimes." Three creatures of Maldrana's choice must succeed on a DC 20 Intelligence saving throw or sink 5 feet into the ground and become restrained. A creature that fails its saving throw while flying takes falling damage if applicable.
The first time Maldrana is bloodied (i.e., falls to half her maximum hit points) : No Strings to Hold Me Down: Maldrana adopts a form of dreams, unrestricted by her claustrophobic environment. Until the next initiative 20, she can pass through solid walls, doors, ceilings, and floors as if the surfaces weren't there. When this effect triggers, she may immediately move up to her move speed without triggering opportunity attacks. If she is inside a creature or solid object when this effect ends, she takes 21 (6d6) force damage and is shunted to the nearest unoccupied space.
Round 3: Castigate the Judged. "You'll get exactly what you deserve, dearie." Maldrana sentences a creature within 60 feet of her that is Judged. The target must make a DC 20 Charisma saving throw or take 37 (5d6+20) necrotic damage and 37 (5d6+20) fire damage. On a successful saving throw, the creature takes half damage. If this damage reduces the creature to 0 HP, it is instantly petrified in a pose of penitence. The petrification lasts until the creature is freed by the greater restoration spell or similar magic.
The region within 1 mile of Maldrana's lair is warped by her will, creating one or more of the following effects. These effects fade after 2d10 days if Madrana dies:
Beasts that have an Intelligence score of 2 or lower are charmed by Maldrana and directed to be aggressive toward intruders in the area. Strange carved figurines, twig fetishes, or rag dolls magically appear in nooks and crevasses in stone.
Creatures may be transported to a harmless but eerie demiplane filled with shadowy forms, waxy corpses, and cackling. The creatures are trapped there for a minute or two, and then returned to the place where they vanished from.
Intelligent creatures see hallucinations of dead friends, family members, and even themselves littering the hag's realm. Any attempt to interact with a hallucinatory image causes it to disappear.
Maldrana carries two very rare magic items that she must craft for herself. If either object is lost, she will go to great lengths to retrieve it, as creating a new tool takes time and effort. Heartstone: This lustrous black gem allows a night hag to become ethereal while it is in her possession. The touch of a heartstone also cures any disease. Crafting a heartstone takes 30 days. Soul Bag: When an evil humanoid dies as a result of a night hag's Nightmare Haunting, the hag catches the soul in this black sack made of stitched flesh. A soul bag can hold only one evil soul at a time, and only the night hag who crafted the bag can catch a soul with it. Crafting a soul bag takes 7 days and a humanoid sacrifice (whose flesh is used to make the bag).