Glasya

Medium Fiend (Devil), Lawful Evil

AC: 21

Initiative: +9 (19)

HP: 380 (40d8 + 200)

Speed: 40 ft., fly 80 ft.

STR: 22 (+6)
DEX: 28 (+9)
CON: 20 (+5)
INT: 21 (+5)
WIS: 25 (+7)
CHA: 28 (+9)

Saving Throws: Dex +17, Int +13, Wis +15, Cha +17

Skills: Deception +25, Intimidation +17, Perception +15, Persuasion +17, Stealth +25, Survival +15

Resistances: cold; necrotic; radiant; bludgeoning, piercing, slashing from nonmagical attacks that aren't silvered

Immunities: fire; poison

Condition Immunities: charmed; poisoned

Senses: blindsight 60 ft., darkvision 120 ft., Passive Perception 25

Languages: Celestial, Common, Draconic, Infernal, telepathy 120 ft.

CR: 25 (XP 75,000; PB +8)

Charm Aura.

When a creature moves to be within 120 feet of Glasya, they must succeed on a DC 23 Wisdom saving throw or have the charmed condition, treating Glasya as an ally, until they leave the aura. A creature that succeeds the saving throw is immune to this effect for 1 hour. Whenever a charmed creature takes damage, they may repeat the saving throw, ending the effect on a success.

Dominating Presence.

Glasya deals an additional 13 (2d12) psychic damage when attacking a charmed creature, and her attacks don't break charms.

Fiendish Regeneration.

Glasya regains 20 hit points at the start of her turn. If she takes radiant damage this trait doesn't function at the start of her next turn. Glasya dies only if she starts her turn with 0 hit points and is unable to regenerate. If Glasya is killed, her body slowly regenerates, returning to life 9 (2d8) weeks later.

Legendary Resistance (3/Day).

If Glasya fails a saving throw, she can choose to succeed instead.

Magic Resistance.

Glasya has advantage on saving throws against spells and other magical effects.

Actions

Multiattack.

Glasya makes four attacks using Scourge of Shadow, Necrotic Grasp, or a combination of the two. She can replace one of the attacks with Mesmerizing Gaze.

Scourge of Shadow.

Melee Weapon Attack: +20 to hit, reach 10 ft., one target. Hit: 19 (3d4 + 12) slashing damage, plus 5 (2d4) necrotic damage. This attack scores a critical on a roll of 18, 19, or 20.

Necrotic Grasp.

Glasya summons necrotic hands to grope and claw at a creature she can see within 90 feet of her. The target must make a DC 25 Constitution saving throw, taking 20 (2d10 + 9) necrotic damage on a failed save, or half as much damage on a successful one.

Mesmerizing Gaze.

Glasya focuses her gaze in a 60-foot cone in front of her. Each creature of her choice within the cone must make a DC 23 Charisma saving throw or have the charmed condition until the end of their next turn. While charmed, creatures automatically fail saving throws from abilities used by Glasya and move to be as close to her as possible.

Deathly Exclamation (1/Day).

Glasya targets a creature she can see within 60 feet of her. The target must make a DC 25 Constitution saving throw, taking 61 (7d8 + 30) necrotic damage on a failed save, or half as much damage on a successful one. A Humanoid killed by this ability rises at the start of Glasya's next turn as a zombie permanently under her command.

Legendary Actions

Legendary Action Uses: 3. Immediately after another creature’s turn, this creature can expend a use to take one of the following actions; it regains all expended uses at the start of each of its turns.

Whip.

Glasya makes a Scourge of Shadow attack.

Disorient (Costs 2 Actions).

Glasya casts Confusion (30-foot-radius, spell save DC 25), but only lasting until the end of Glasya's next turn.

Call Underling (Costs 3 Actions).

Glasya summons an allied erinyes in an unoccupied space that she can see.

Lair Actions

On initiative count 20 (losing initiative ties), Glasya can take one lair action to cause the following effect or one from the archdevil lair action list (page 214); she can't take the same lair action two rounds in a row:

Change Appearance.
Glasya polymorphs into a Small or Medium Humanoid she has seen, or back into her true form. Her statistics, other than her size, 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.

Attack.
The archdevil uses one of their available melee or ranged attacks against a single foe.
Cast a Spell.
The archdevil uses their Spellcasting feature to cast an available spell. If the spell normally requires concentration, it lasts for the full duration instead.
Deceitful Whispers.
The archdevil whispers to a creature they can see within 30 feet. The target must make a DC 22 Wisdom saving throw. On a failed save, the target has the charmed condition until the start of their next turn and must use their reaction immediately to make an attack against one of the archdevil's enemies, chosen by the archdevil.
Fiendish Fortitude.
The archdevil recharges one of their expended abilities.
Frenzy.
The archdevil casts Haste on themself. The effect ends at initiative count 20 of the next round.
Summon Underlings.
The archdevil summons allied devils. The devils summoned depends on the archdevil using this feature. The summoned devils appear in unoccupied spaces which the archdevil can see. The Summoned Underlings table shows which devils each archdevil can summon.
Teleport.
The archdevil teleports themself to an area they can see within 120 feet.
Trap.
The archdevil casts the Hold Monster spell.

Regional Effects

The region containing Glasya's lair is corrupted by her presence, which creates the following effect:

Hag's Gaze.
Every hour that a good creature travels within 1 mile of the lair, a blast of fire erupts from one of the eye sockets of the lair. If the target fails a DC 23 Dexterity saving throw, they take 42 (12d6) fire damage, half on a successful save. If the creature was flying and fails the saving throw, it falls. Only one such creature is targeted each hour.

If Glasya dies, the effects fade over the course of 1d10 days.

Find this creature in the encounter builder

Source: Chains of Asmodeus, p. 226 - Licenses and attribution