Avatar of Fire

Fire Form: A creature that touches the Avatar of Fire or hits it with a melee attack while within 5 feet takes 10 (3d6) fire damage.

Molten Body: When the Avatar of Fire takes cold damage, it is slowed until the end of its next turn. While slowed, it loses its Legendary Actions for that round.

Legendary Resistance (3/Day): If the Avatar of Fire fails a saving throw, it can choose to succeed instead.

Multiattack: The Avatar of Fire makes two melee attacks.

Molten Slam: Melee Weapon Attack. +12 to hit, reach 10 ft., one target. Hit: 21 (3d10 + 7) bludgeoning and fire damage. If the target is a creature, it must succeed on a DC 18 Strength saving throw or be knocked prone.

Flame Whirlwind (Recharge 5-6): The Avatar of Fire spins violently, creating a 30-foot radius firestorm. Each creature in range must make a DC 17 Dexterity saving throw, taking 33 (6d10) fire damage on a failed save or half as much on a success. The area ignites, burning for 1 round.

Lava Strike (Recharge 4-6): The Avatar of Fire slams the ground, causing lava to burst forth in a 20-foot line, 5 feet wide. Each creature in the area must make a DC 17 Dexterity save, taking 27 (6d8) fire damage on a failed save, or half on success. The ground in the area becomes molten lava for 1 minute, dealing 3d8 fire damage to any creature starting its turn there.

The Avatar of Fire can take three legendary actions, choosing from the options below. It can only use one per turn and regains spent actions at the start of its turn.

Ignite: One creature within 10 feet bursts into flames. Until it spends an action to extinguish the fire, it takes 7 (2d6) fire damage at the start of each of its turns.

Burning Dash: Moves 20 feet without provoking opportunity attacks, leaving a burning trail behind. The trail burns for 1 round, dealing 2d8 fire damage to any creature that crosses it.

Meteor Slam (2 Actions): Jumps into the air and crashes down within 30 feet. Each creature in a 10-ft radius must make a DC 18 Strength save or take 22 (4d8 + 7) bludgeoning damage and be knocked prone.

When the Avatar of Fire is reduced to 0 HP for the first time, it erupts in a catastrophic explosion.

• All creatures within 40 feet must make a DC 18 Dexterity saving throw.
• On a failed save: Creatures take 42 (12d6) fire damage and are knocked prone.
• On a success: They take half damage and are not knocked prone.

The arena floor fractures, causing lava to seep up, making the terrain even more hazardous.The Avatar of Fire then fully heals to 145 HP, becoming the Living Volcano and gaining Mythic Actions.While in Volcano Form, the Avatar of Fire has all previous abilities plus the following:

• Volcanic Wrath (Costs 2 Actions): Spews lava over a 30-ft cone. Each creature in the area must make a DC 18 Dexterity save or take 35 (10d6) fire damage.
• Burning Winds (1 Action): A fiery cyclone sweeps the arena. Each creature must make a DC 16 Strength saving throw or be pushed 20 feet in a random direction and take 3d8 fire damage.
• Final Judgment (3 Actions, Once Per Battle): In 2 rounds, the arena will fully collapse into magma. The Avatar of Fire flies 40 feet into the air and erupts, causing flaming boulders to crash down in random locations. Each creature makes a DC 17 Dexterity save, taking 27 (6d8) fire damage or half on a success. This repeats at the start of its turns.