Burning Maiden

Immutable Form. The Maiden is immune to any spell or effect that would alter its form.

Construct Nature. The Maiden doesn't require air, food, drink, or sleep.

Fire Absorption. Whenever the Maiden is subjected to fire damage, it takes no damage and instead regains a number of hit points equal to the fire damage dealt. Additionally, if the damage was caused by a spell, the time remaining on its Start-Up Mechanic is increased by 5 minutes.

Heated Body. A creature that touches the Maiden or hits it with a melee attack while within 5 feet of it takes 10 (3d6) fire damage.

Burning Aura. At the start of each of the Maiden's turns, each creature within 10 feet of it takes 14 (4d6) fire damage. Any creature that starts its turn in this area must succeed on a DC 17 Constitution saving throw or have disadvantage on attack rolls until the start of its next turn. This effect harms all creatures, including allies of the Maiden.

Magic Fuel. Whenever a creature dies while engulfed by the Maiden, or whenever the Maiden successfully drains a spell slot (see below), the Maiden regains 20 hit points, all its attacks deal an extra 10 (3d6) fire damage until the end of its next turn, and the time remaining on its Start-Up Mechanic is increased by 10 minutes.

Reactive Annihilation. When a creature moves into a space within 10 feet of the Burning Maiden for the first time on a turn, the Maiden can use its reaction to make one Mace of Incineration attack against that creature.

Start-Up Mechanic. The Maiden begins the encounter in an Inert State and is Prone. While inert, it has an AC of 10, is immune to all damage, and cannot take actions or reactions. To activate it (for the first time or after its time runs out), one of the following must occur:

• A creature uses an action to force a Fire Elemental to enter the Maiden's space.

• A creature casts a fire-based spell of 3rd level or higher (such as fireball) on the Maiden.

  Once activated, it is active for 1 hour. The remaining time is reduced by 6 seconds at the start of each of its turns. If the time runs out, it reverts to its Inert State. The Maiden considers the creature that activated it (and any allies of that creature) as its owner and will not intentionally attack them unless they stand within its Burning Aura or its owner is changed.

Multiattack. The Burning Maiden makes two Mace of Incineration attacks.

Mace of Incineration. Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit: 19 (3d8 + 6) bludgeoning damage plus 14 (4d6) fire damage.

Embrace of Ash (Recharge 5-6). The Maiden attempts to grapple one Large or smaller creature within its reach. It makes a melee attack against the target: +11 to hit. Hit: 13 (2d6 + 6) bludgeoning damage, and the target is grappled (escape DC 17) and subjected to the Maiden's Burning Aura damage immediately, regardless of where its turn is. If the target is a spellcaster, it must also succeed on a DC 17 Intelligence saving throw or the Maiden steals one of the highest level spell slots available to the target. This stolen spell slot is lost to the target. If the creature is a construct or doesn't have spell slots, the Maiden doesn't steal a slot. If the target is a Fire Elemental, it is instantly absorbed, takes no damage, and the Maiden's Start-Up Mechanic time increases by 1 hour.

Consume and Incinerate. The Maiden attempts to move a creature it is grappling into the furnace in its chest. The grappled creature must succeed on a DC 17 Strength saving throw or be engulfed by the Maiden. An engulfed creature is blinded and restrained, it has total cover against attacks and other effects outside the Maiden, and it takes 35 (10d6) fire damage at the start of each of the Maiden's turns. If the engulfed creature is a spellcaster, the damage increases by an amount equal to the level of the highest spell slot the creature possesses (e.g., if they have a level 5 slot, the damage increases by 5). If the Maiden takes 40 or more damage from a single source from an engulfed creature in one turn, it must succeed on a DC 17 Constitution saving throw at the end of that turn or regurgitate all engulfed creatures, which fall prone in a space within 10 feet of the Maiden.

Summon Fire Elementals (1/Day). The Burning Maiden summons two Fire Elementals. The elementals appear in an unoccupied space within 30 feet of the Maiden and act on their own initiative.

Reactive Annihilation. When a creature moves into a space within 10 feet of the Burning Maiden for the first time on a turn, the Maiden can use its reaction to make one Mace of Incineration attack against that creature.