Clethtinthiallor

Death Throes. When Clethtinthiallor dies, she explodes, unless she was killed by cold damage. Each creature within 120 feet of her must make a DC 20 Dexterity saving throw, taking 54 (12d8) fire damage on a failed save, or half as much damage on a successful one. Provided that the Emberglass Zweihander’s curse has not been broken, Clethtinthiallor will reform within the Emberglass Zweihander after 5 (1d10) hours.

Fire Form. Clethtinthiallor can move through a space as narrow as 1 inch wide without squeezing. She cannot be forced to move or have her speed reduced to 0 through physical means, except by solid surfaces or strong winds.

Additionally, a creature that touches Clethtinthiallor takes 17 (3d10) fire damage. In addition, Clethtinthiallor can enter a hostile creature's space and stop there. A creature that starts its turn in Clethtinthiallor’s space or hits her with a melee attack while within 20 feet of her takes 17 (3d10) fire damage and catches fire. Any flammable object within 20 feet of her ignites. Any liquid within 20 feet of her evaporates. When it takes this damage, the creature has disadvantage on attack rolls made against Clethtinthiallor until the end of its turn. Until someone takes an action to douse the fire, the creature takes 17 (3d10) fire damage at the start of each of its turns.

Illumination. Clethtinthiallor sheds bright light in a 60-foot radius and dim light in an additional 60 feet. Spells and other effects that create magical darkness are dispelled if they overlap with the area Clethtinthiallor illuminates.

Magical Weapons. Clethtinthiallor’s attacks are magical.

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

Multiattack. Clethtinthiallor can use her Blinding Flare or Fire Breath. She then makes three attacks.

Bite. Melee Weapon Attack: +17 to hit, reach 15 ft., one target. Hit: 21 (2d10+10) piercing damage plus 18 (4d8) fire damage. If the target is a creature or a flammable object, it ignites. Until a creature takes an action to douse the fire, the target takes 17 (3d10) fire damage at the start of each of its turns.

Claw. Melee Weapon Attack: +17 to hit, reach 10 ft., one target. Hit: 17 (2d6+10) slashing damage plus 18 (4d8) fire damage. If the target is a creature or a flammable object, it ignites. Until a creature takes an action to douse the fire, the target takes 17 (3d10) fire damage at the start of each of its turns.

Tail. Melee Weapon Attack: +17 to hit, reach 20 ft., one target. Hit: 19 (2d8+10) bludgeoning damage plus 18 (4d8) fire damage. If the target is a creature or a flammable object, it ignites. Until a creature takes an action to douse the fire, the target takes 17 (3d10) fire damage at the start of each of its turns.

Wing Attack. Clethtinthiallor beats her wings. Each creature within 15 feet of the elemental must succeed on a DC 25 Dexterity saving throw or take 17 (2d6 + 10) bludgeoning damage plus 18 (4d8) fire damage and be knocked prone. Clethtinthiallor can then fly up to half her flying speed. Any creature or flammable object within range of the attack ignites. Until a creature takes an action to douse the fire, the target takes 17 (3d10) fire damage at the start of each of its turns.

Fire Storm. Ranged Spell Attack. +17 to hit, ranged 300 ft. A storm made up of roaring flames appears within range. Each creature in the area must make a Dexterity saving throw. It takes 77 (14d10) fire damage on a failed save, or half as much damage on a successful one.
The fire damages objects in the area and ignites flammable objects that aren’t being worn or carried. The storm takes 4 (1d8) turns to dispel.

Fire Breath. (Recharge 5-6). Clethtinthiallor exhales fire in a 90-foot cone. Each creature in that area must make a DC 24 Dexterity saving throw, taking 91 (26d6) fire damage on a failed save, or half as much damage on a successful one. If the target is a creature or a flammable object, it ignites. Until a creature takes an action to douse the fire, the target takes 17 (3d10) fire damage at the start of each of its turns.

Blinding Flare. (Recharge 5-6). Clethtinthiallor burns blindingly bright for a moment. Each creature within 60 feet of Clethtinthiallor that can see her must make a DC 21 Constitution saving throw or be blinded for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Clethtinthiallor can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn. Clethtinthiallor regains spent legendary actions at the start of her turn.

Frightful Presence. Each creature of Clethtinthiallor's choice that is within 120 ft. of the elemental and aware of her must succeed on a DC 21 Wisdom saving throw or become frightened for 5 minutes. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to Clethtinthiallor's Frightful Presence for the next 24 hours.

Burn. Clethtinthiallor chooses a creature she can see that is currently on fire. The target takes 17 (3d10) fire damage, and must succeed on a DC 21 Constitution saving throw or suffer disadvantage on attack rolls and ability checks until it is no longer on fire.