Cronerort (updated version)

Death Throes. When the balor dies, it explodes, and each creature within 30 feet of it must make a DC 20 Dexterity saving throw, taking 70 (20d6) necrotic 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 with a black fire that deals necrotic damage, and it destroys the balor's weapons, is it carries any.

Soul Fire Aura. At the start of each of the balor's turns, each creature within 5 feet of it takes 37 (9d6+7) necrotic damage. A creature that touches the balor or hits it with a melee attack while within 5 feet of it takes 20 (3d6x2) necrotic 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 and deal 45 extra necrotic damage. The valor does not carry weapons regularly.

Dark Wing(1/ new moon) one creature of the balor's choice takes 155 necrotic damage if they fail a DC 19 dexterity saving throw.

Shadow Blast from the balor's mouth comes a beam of darkness that continues until it hits an object. the first thing the beam hits takes 25 (5d10) necrotic damage.