Death Throes. When the balor dies, it explodes, and each creature within 30 feet of it must make a DC 21 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 balor's weapons.

Lightning Aura. At the start of each of the balor's turns, each creature within 5 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 balor or hits it with a melee attack while within 5 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 (2/Day). If Admaer fails a saving throw, he can choose to succeed instead.

Innate Spellcasting. The balor's innate spellcasting ability is Charisma (spell save DC 22). It can innately cast a number of spells, requiring no material components:

1/day each: Shield, Counterspell, Misty Step, Fireball.

Shapechanger. Admaer can use his action to polymorph into a form that resembles a Medium humanoid, or back into its true form. Aside from its size, its statistics are the same in each form. Any equipment it is wearing or carrying isn't transformed.

 Regeneration. Admaer regains 15 hit points at the start of his turn. If he takes radiant damage, this trait doesn't function at the start of his next turn. Admaer dies only if he starts his turn with 0 hit points and doesn't regenerate.

Multiattack. The balor makes two attacks: one with its longsword and one with its whip.

Longsword. Melee Weapon Attack: +16 to hit, reach 10 ft., one target. Hit: 21 (3d8 + 9) slashing damage plus 13 (3d8) lightning damage. If the balor scores a critical hit, it rolls damage dice three times, instead of twice.

Whip. Melee Weapon Attack: +16 to hit, reach 30 ft., one target. Hit: 15 (2d6 + 9) slashing damage plus 10 (3d6) poison damage, and the target must succeed on a DC 21 Strength saving throw or be pulled up to 25 feet toward the balor.

Teleport. The balor magically teleports, along with any equipment it is wearing or carrying, up to 120 feet to an unoccupied space it can see.