Avatar of the Elements

Elemental Fury: The Avatar of the Elements deals an additional 1d8 damage of a randomly determined type (fire, cold, lightning, or thunder) with its melee attacks.

Magic Resistance. The Avatar of the Elements has advantage on saving throws against spells and other magical effects.

Elemental Mastery. The Avatar of the Elements can cast fireball, cone of cold, lightning bolt, and thunderwave as 5th-level spells. Its spellcasting ability is Intelligence (spell save DC 15).

Multiattack. The Avatar of the Elements makes two melee attacks.

Elemental Strike. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 18 (2d10 + 6) bludgeoning damage plus 9 (2d8) elemental damage.

Elemental Blast. The Avatar of the Elements unleashes a blast of elemental energy in a 20-foot cone. Each creature in that area must make a DC 18 Dexterity saving throw, taking 36 (8d8) elemental damage on a failed save, or half as much damage on a successful one. The type of elemental damage is determined randomly:

1. Fire
2. Cold
3. Lightning
4. Thunder

Whirlwind. Once per day, the Avatar of the Elements can create a whirlwind of elemental force in a 15-foot radius centered on itself. Each creature in that area must make a DC 18 Strength saving throw or be knocked prone and take 22 (4d10) bludgeoning damage. On a successful save, the creature takes half as much damage and isn't knocked prone. The whirlwind lasts for 1 minute or until the Avatar of the Elements uses its action to end it.

Stone Barrier. As a reaction, when the Avatar of the Elements is hit by a ranged attack, it can create a barrier of stone, granting itself partial cover until the start of its next turn.

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