Volgameth, the Charged

Death Throes. When Volgameth, the Charged dies, it explodes, and each creature within 30 feet of it must make a DC 20 Dexterity saving throw, taking 70 (20d6) Lightning damage on a failed save, or half as much damage on a successful one. The explosion ignites flammable objects in that area that aren't being worn or carried, and it destroys the Volgameth, the Charge's weapons.

Shock Aura. At the start of each of the Volgameth, the Charge's turns, each creature within 10 feet of it takes 10 (3d6) Lightning damage, and flammable objects in the aura that aren't being worn or carried ignite. A creature that touches the Volgameth, the Charged or hits it with a melee attack while within 10ft feet of it takes 10 (3d6) Lightning damage.

Magic Resistance. The balor has advantage on saving throws against spells and other magical effects.

Magic Weapons. The balor's weapon attacks are magical.

Legendary Resistance (3 per Day).  If Volgameth, the Charged fails a saving throw.  They can choose to succeed instead.

Innate Spellcasting. Volgameth, the Charge's spell casting ability modifier is Charisma (Spell DC Save 21). It can innately cast the following spells spells requiring no material components.

3/day each: Lightning Bolt

1/day each: Banishment

Lava Field. Volgameth, the Charged as a bonus action can cause magma to explode out of the ground causing 7(2d6) fire damage on a failed dexterity saving throw DC 17 or half as much damage on a success to a creature with in 15 feet .

Multiattack. Volgameth, the Charged makes two attacks: one with its longsword and one with its Plasma Gauntlet.

Longsword. Melee Weapon Attack: +15 to hit, reach 10 ft., one target. Hit: 21 (3d8 + 8) slashing damage plus 13 (3d8) lightning damage. If Volgameth, the Charged scores a critical hit, it rolls damage dice three times, instead of twice.

Plasma Gauntlet. Melee Weapon Attack: +15 to hit, reach 30 ft., one target. Hit: 15 (2d6 + 8) piercing damage plus 10 (3d6) fire damage, and the target must succeed on a DC 20 Strength saving throw or be pushed or pulled up to 25 feet away or toward Volgameth, the Charged.

Etherealness. Volgameth, the Charged can enter the Ethereal plane at will, but must spend at least 1 minute standing still.

Voltaic Arch. Volgameth, the Charged can send an arc of lightning at any creature with in 60 feet of it doing 14 (4d6) Lightning Damage when it is hit by an attack.

Volgameth, the charged has 3 legendary reactions, and can only use them at the end of a creatures turn.  Volgameth, the charge regains its legendary actions at the start of its turn

Move (Costs 1 Legendary Action). Volgameth, the Charged can move up to its speed without provoking opportunity attacks.

Rampage (Costs 2 Legendary Actions). Volgameth, the Charged makes two attacks, one with its plasma gauntlet and one with its longsword.

Teleport (Cost 2 Legendary Actions). Volgameth, the Charged magically teleports, along with any equipment it is wearing or carrying, up to 120 feet to an unoccupied space it can see.

 Summon Hounds (Costs 3 Legendary Actions). Volgameth, the Charged can summon 1d4+1 Hell Hounds (Only can be used once per day).