Avatar of Evil Elemental Fire

Illumination. The Avatar of Evil Elemental Fire sheds bright light in a 60-foot radius and dim light in an additional 30 feet.

Death-Throes. When the avatar dies, it explodes and all targets within 300 feet of it must make a DC 17 Dexterity saving throw or take 10d8 fire damage, or half on a success. The explosion destroys the creature and anything it wields or carries, except the mask it wears.

Reactive. The avatar can take a reaction on every turn of combat.

Roaring Flame. The avatar has an advantage on attack rolls against burning targets. Additionally, targets already on fire take an additional 2d8 fire damage when hit by its attacks.

Multiattack. The avatar can make 3 attacks with its fire-sword or 6 ignition attacks. 1 longsword attack can be replaced with two ignitions.

Longsword. Melee Weapon Attack: +12 to hit, reach 30 ft., one target. Hit: (2d8 + 3 slashing damage and 2d8 fire damage), and the target must succeed on a DC 17 Dexterity saving throw or begin burning. At the end of each of their turns, the target must attempt to succeed again on the saving throw or take 2d8 fire damage. The flames cannot be extinguished through nonmagical means.

Ignite. Ranged Spell Attack: +10 to hit, reach 120 ft., one target. Hit: (2d8 fire damage), and the target must succeed on a DC 17 Dexterity saving throw or begin burning. At the end of each of their turns, the target must attempt to succeed again on the saving throw or take 2d8 fire damage. The flames cannot be extinguished through nonmagical means.

Igniting Rebuke. When a target within 30 ft. of the avatar hits it with an attack, the avatar can make one ignite attack against that creature.

Heat Wave. Everyone in 500 ft. of the Avatar of Evil Elemental Fire who is not immune to fire damage must make a DC 16 Consitution saving throw, otherwise, they take 1d6 fire damage from contact with metal weapons or armor, and take 1 level of exhaustion.