Illumination. Brynhildr sheds bright light in a 60-foot radius and dim light for an additional 60 feet.
Kinetic Slag Overheat. Brynhildr’s molten skin is coated in highly reactive, pressurized kinetic slag. Whenever a creature hits her more than twice on a single turn with melee weapon attacks, the sudden friction triggers a violent back-blast. For every successful hit after the second on that turn, the attacker takes 13 (2d12) fire damage from the exploding basalt.
Legendary Resistance (3/Day). If Brynhildr fails a saving throw, she can choose to succeed instead.
Water Susceptibility. For every 5 feet Brynhildr moves in water, or for every gallon of water splashed on her, she takes 1 cold damage. If she takes cold damage from an external spell or weapon, her obsidian armor plates harden; her Armor Class increases by 1 until the start of her next turn, but her movement speed is halved during that time.
Multiattack. Brynhildr makes three attacks: one with her Magma Slam and two with her Siphoning Tendrils. Alternatively, she uses her Volcanic Vent Discharge twice.
Magma Slam. Melee Weapon Attack: +15 to hit, reach 15 ft., one target. Hit: 27 (3d12 + 8) bludgeoning damage plus 13 (2d12) fire damage. If the target is a creature wearing metal armor, its armor plates heat up instantly; the creature takes 7 (2d6) fire damage at the start of its next turn unless the armor is cooled or targeted by a spell that removes heat.
Siphoning Tendril. Melee Spell Attack: +12 to hit, reach 20 ft., one target. Hit: 17 (4d6 + 3) fire damage. If the target has unexpended spell slots or active magical transformations, it must succeed on a DC 20 Charisma saving throw or lose one unexpended spell slot of the highest level it currently possesses, or have its transformation instantly end. Brynhildr regains 10 hit points whenever a spell slot or transformation is successfully siphoned in this manner.
Volcanic Vent Discharge. Ranged Spell Attack: +12 to hit, range 120 ft., one target. Hit: 22 (4d8 + 4) fire damage plus 11 (2d10) bludgeoning damage as rock debris breaks the target’s stance.
Tectonic Collapse (Recharge 5–6). Brynhildr violently drives her massive lower frame into the bedrock, triggering a localized earthquake in a 60-foot-radius sphere centered on herself. Each creature standing on the ground in that area must make a DC 25 Strength saving throw. On a failed save, a target takes 45 (10d8) bludgeoning damage and is knocked Prone beneath shifting boulders. On a successful save, a target takes half damage and is not knocked prone.
Tectonic Deflection (3). When Brynhildr is hit by a weapon attack, she can use a reaction to cause a localized volcanic pillar to erupt beneath the attacker’s feet. The attacker must succeed on a DC 23 Dexterity saving throw or take 11 (2d10) fire damage and be pushed 10 feet away. Brynhildr tracks each use of this reaction individually and regains all expended uses at the start of her turn.
Brynhildr can take 3 legendary actions, choosing from the options below. Only one option can be used at a time and only at the end of another creature’s turn. She regains spent actions at the start of her turn.
Molten Displacement. Brynhildr melts down into the floor, instantly burrowing up to her speed through magma or stone without provoking opportunity attacks.
Tendril Strike (Costs 2 Actions). Brynhildr makes one Siphoning Tendril attack.
Seismic Realignment (Costs 3 Actions). Brynhildr stamps her foot, forcing a target she can see within 90 feet to make a DC 20 Intelligence saving throw. On a failure, Brynhildr forcefully swaps that character’s position on the battlefield with another companion or an active lava hazard pool, completely breaking the party’s defensive perimeter.
Magmatic Back-Blast. When damage reduces Brynhildr to 0 hit points, she does not instantly perish. Instead, her core undergoes complete thermal destabilization, triggering a massive, final eruption before her molten form permanently hardens into stagnant stone. Each creature within a 60-foot-radius sphere centered on Brynhildr must make a DC 25 Constitution saving throw. On a failed save, a target takes 71 (13d10) fire damage and is knocked Prone by the sonic boom. On a successful save, a target takes half damage and is not knocked prone. Following this explosion, Brynhildr’s physical shell solidifies into stone, and she collapses into a non-magical monument of volcanic rock.
Description
The Local Parasite — Sovereign of the Deep Magma Roots
Deep within the subterranean magma veins and volcanic foundations stretching beneath Kervaash’s flat-topped mesas, Brynhildr, the Smoldering Core endures as an unyielding parasitic anchor. She is not a deity born of cosmic design, but a primordial anomaly whose very form is composed of molten basalt, cooling obsidian plating, and a continuous crown of super-heated, blinding plasma. For centuries, she has maintained a quiet, parasitic relationship with the mortal settlements above. Every basic heat-orb conjured by a village hedge-wizard and every minor fire elemental bound to a town hearth directly siphons from her dwindling domain. She is the hidden, volcanic spark that prevents the slow-growing EverFyr wood from freezing solid, making her a vital lifeline for mortal survival in the northern drop zones.
Yet, this thermal dependency masks a severe continental threat. To feed her surface flames and preserve her own fading existence, Brynhildr systematically drains the immense tectonic pressure of the ocean floors. This continuous siphoning triggers catastrophic undersea earthquakes and massive volcanic vents that choke the southern straits with boiling sulfur sheets and groaning ice flows. By stabilizing the northern settlements, she is systematically isolating Kervaash from the rest of the world, creating a localized planetary fault line that must be forcefully corrected and balanced by the Monolith’s operatives.
Lair and Lair Actions
The Mother of Magic permanently bends the weave within her sanctum. On initiative count 20 (losing initiative ties), Mystra can take a lair action to cause one of the following effects; she cannot use the same option two rounds in a row:
Pāhoehoe Surge. Brynhildr forces the surrounding magma pools to boil over. A 10-foot-wide wave of viscous, super-heated lava sweeps along a 60-foot line across the stone floor. Each creature standing in that area must make a DC 24 Dexterity saving throw. On a failed save, a target takes 35 (10d6) fire damage and has its movement speed halved until the start of its next turn as the cooling rock solidifies around its boots. On a successful save, a target takes half damage and its speed is not reduced.
Slag-Dust Whiteout. A dense cloud of blinding sulfur gas and hot obsidian ash explodes from a fissure within 90 feet of Brynhildr, filling a 30-foot-radius sphere. The area becomes heavily obscured until initiative count 20 on the next round. Any creature that starts its turn inside the cloud must succeed on a DC 24 Constitution saving throw or take 21 (6d6) fire damage and become completely Blinded until the start of its next turn.
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