Elemental Overlord

Medium humanoid (any race), any alignment

Armor Class 13 (16 with mage armor)
Hit Points 165 (30d8 + 30)
Speed 30 ft.

STR	DEX	CON	INT	WIS	CHA
10 (+0)	16 (+3)	13 (+1)	14 (+2)	15 (+2)	21 (+5)

Saving Throws Dexterity +8, Constitution +6, Charisma +10
Skills Arcana +7, Intimidation +10, Persuasion +10
Damage Immunities varies (see Elemental Flexibility)
Senses passive Perception 12
Languages any three languages
Challenge 14 (11,500 XP)

Special Traits

• Elemental Flexibility. At the start of its turn, the elemental overlord must choose one damage type: acid, cold, fire, or lightning. It has immunity to its chosen damage type until the start of its next turn. It can’t choose the same damage type two rounds in a row.
• Elemental Shield. A creature that touches the elemental overlord or hits it with a melee attack while within 5 feet of it takes 10 (3d6) damage of the type chosen with Elemental Flexibility.
• Legendary Resistance (3/day). If the elemental overlord fails a saving throw, it can choose to succeed instead.
• Spellcasting. The elemental overlord is a 20th-level spellcaster. Its spellcasting ability is Charisma (spell save DC 18, +10 to hit with spell attacks). The overlord has the following wizard spells prepared:
• Cantrips (at will): acid splash, blade ward, fire bolt, light, prestidigitation
• 1st level (4 slots): burning hands, detect magic, mage armor, magic missile, shield
• 2nd level (3 slots): blur, flaming sphere, gust of wind, misty step
• 3rd level (3 slots): counterspell, fly, lightning bolt
• 4th level (3 slots): conjure minor elementals, ice storm, stoneskin, wall of fire
• 5th level (3 slots): cone of cold, conjure elemental, wall of stone
• 6th level (2 slots): chain lightning, wall of ice
• 7th level (2 slots): delayed blast fireball, prismatic spray
• 8th level (1 slot): control weather
• 9th level (1 slot): meteor swarm

Actions

• Dagger. Melee or Ranged Weapon Attack: +8 to hit, reach 5 ft. or range 20/60 ft., one target. Hit: 5 (1d4 + 3) piercing damage.
• Elemental Bolt. Ranged Spell Attack: +10 to hit, range 120 ft., one target. Hit: 28 (8d6) damage of the type chosen with Elemental Flexibility, and the target must succeed on a DC 18 Constitution saving throw or have disadvantage on its next saving throw against a spell cast by the elemental overlord.

Legendary Actions

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

• Cantrip. The elemental overlord casts a cantrip.
• Move. The elemental overlord moves up to half its speed without provoking opportunity attacks.
• Elemental Bolt (costs 2 actions). The elemental overlord makes one Elemental Bolt attack.
• Power Uncontained (costs 3 actions). The elemental overlord releases a burst of elemental energy. Each creature within 20 feet of it must make a DC 18 Dexterity saving throw. On a failure, a creature takes 21 (6d6) force damage and is pushed up to 10 feet away and knocked prone. On a success, a creature takes half the damage and isn’t pushed or knocked prone.