monster

Fierna

CR 25

Medium Fiend (devil), Lawful Evil

Reveal Stat Block

Armor Class

20 (natural armor)

Hit Points

367 (35d8 + 210)

Speed

30 ft., fly 60 ft.

str

dex

con

int

wis

cha

Traits

Fear Aura.When a creature starts their turn within 120 feet of Fierna, they must succeed on a 22 Wisdom saving throw or have the frightened condition until they leave the aura. A creature that succeeds on the saving throw is immune to this effect for 1 hour.

Fiendish Regeneration.Fierna 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. Fierna dies only if she starts her turn with 0 hit points and is unable to regenerate.

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

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

Princess of Hellfire.Fire conjured by Fierna becomes Hellfire. It ignores resistances and immunities to fire damage, deals double damage to creatures vulnerable to fire or necrotic damage, can't be extinguished through any means, and is capable of melting stone or igniting inflammable objects.

Actions

Multiattack.Fierna makes three attacks using Flame Blade, Mote of Flame, or a combination of the two.

Flame Blade.ms 20 to hit, reach 5 ft., one target. ({@damage 4d6 + 9) fire damage.

Mote of Flame.Fierna targets a creature she can see within 90 feet of her. The target must make a 25 Dexterity saving throw, taking 22 (3d8 + 9) fire damage on a failed save, or half as much damage on a successful one.

Legendary Actions.The creature can take 3 legendary actions...

Blade.Fierna makes a Flame Blade attack.

Conjure Hellfire (Costs 2 Actions).Fierna chooses a point she can see within 150 feet of her. All creatures in a 20-foot-radius sphere centered on that point must make a 25 Dexterity saving throw, taking 28 (8d6) fire damage on a failed save, or half as much damage on a successful one.

Call Underling (Costs 3 Actions).Fierna summons an allied spined devil in an unoccupied space that she can see.

Reactions.Reactions the creature can take:

Wreath of Flames.When hit by a melee attack and Fierna can see her attacker, she covers herself in Hellfire, and the attacker takes 13 (3d8) fire damage.

Fierna

Fierna rules Phlegethos alongside her father, Belial. She is emotionally intelligent, and her charisma has earned her many allies and few enemies in the Nine Hells. Although some view her as incompetent, Fierna's true intentions are hidden behind a smokescreen of brashness.

Her father, Belial, was a key player in the Reckoning, and due to his actions, Fierna was granted primary leadership of Phlegethos. Despite this political appearance, Fierna and Belial rule together, often meeting in secret to discuss strategy and upcoming plans. Some of the more ignorant archdevils view the relationship between Belial and Fierna as something to be exploited or broken. In reality, Fierna deeply respects her father, and the feeling is mutual.

Laying eyes on Fierna, one can immediately see the reasons she is so admired: she is impossibly beautiful. Her beauty is a strength, complementing her strategic mind and ingenuity.

Fierna's Lair

Fierna's lair is a palace, a tower of crystalline stone wreathed in blue flame.