Infernal Plating (3 Plates). If Ziatora fails a saving throw or takes a critical hit, she can choose to shed an armor plate. This allows her to succeed on saving throws and deny critical hits at a cost. Whenever she does this, the range of her Aura of Incineration decreases by 10 feet, the damage mitigation granted by her Obsidian Scales decreases by 1, the number of attacks in her Multiattack decreases by 1, and her Armor Class decreases by 2.

Aura of Incineration. Ziatora has an aura that extends 30 feet away from her. When a creature enters the aura for the first time on a turn or starts its turn there, it must make a DC 20 Constitution saving throw. On a failed save, the creature takes 3 fire damage and becomes vulnerable to fire damage until the start of its next turn. Creatures that are resistant to fire damage have advantage on the saving throw and creatures that are immune to fire damage are unaffected.

Obsidian Scales. Ziatora takes 3 less damage from all incoming damage sources.

Multiattack. Ziatora makes three attacks: one with her bite and two with her claws.

Bite. Melee Weapon Attack: +16 to hit, reach 15 ft., one target. Hit: 19 (2d10 + 8) piercing damage plus 7 (2d6) fire damage.

Claw. Melee Weapon Attack: +16 to hit, reach 10 ft., one target. Hit: 15 (2d6 + 8) slashing damage.

Fire Breath (Recharge 5–6). Ziatora exhales fire in a 60-foot cone. Each creature in that area must make a DC 20 Dexterity saving throw, taking 63 (18d6) fire damage on a failed save, or half as much damage on a successful one.

Crushing Tail. Ziatora sweeps her tail in a 20-foot cone. Each creature in the area must make a DC 20 Strength saving throw. On a failed save, the creature takes 15 (2d6 + 8) bludgeoning damage and is knocked 10 feet away from her. On a successful save, the creature takes half damage and isn't pushed.

Sacrifice Soul. Ziatora sacrifices a blood witch for a boon from Rakdos. Ziatora regains 12 hit points, a missing armor plate, and all the abilities that she lost from shedding the plate.

Ziatora has three villain actions. She can take each action once during an encounter after an enemy creature’s turn. She can take these actions in any order but can only use one per round.

Action 1: Fly Children!!! All enemy creatures within 15 feet of Ziatora or her wyrmlings must make a DC 22 Dexterity saving throw (DC 14 for wyrmlings). On a failed save, the creature takes 17 (2d6 + 10) bludgeoning damage and is knocked prone. Ziatora and her wyrmlings can then fly up to half of their flying speed. 

Action 2: Burn to Dust!!! Ziatora exhales fire and creates a 60-foot long wall of fire (DC 20 Dexterity saving throw). Unlike the spell, both sides of the wall deal 22 (5d8) damage when a creature ends its turn within 10 feet of it. The wall lasts for 1 minute.

Action 3: Never... Again!!! Ziatora ends an incapacitating condition that is affecting her and immediately recharges her Fire Breath. She then gains the benefits of freedom of movement and the range of her Aura of Incineration increases by 30 feet. These bonuses last for 1 minute.