Balor
Huge Fiend (demon), chaotic evil
22,000 XP
Special Abilities
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) fire 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.
Fire Aura
At the start of each of the balor's turns, each creature within 5 feet of it takes 10 (3d6) fire 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) fire 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.
Actions
Multiattack
The balor makes two attacks: one with its longsword and one with its whip.
Longsword
Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 21 (3d8 + 8) 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: +14 to hit, reach 30 ft., one target. Hit: 15 (2d6 + 8) slashing damage plus 10 (3d6) fire damage, and the target must succeed on a DC 20 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.
Variant: Summon Demon (1/Day)
The demon chooses what to summon and attempts a magical summoning.
A balor has a 50 percent chance of summoning 1d8 vrocks, 1d6 hezrous, 1d4 glabrezus, 1d3 nalfeshnees, 1d2 mariliths, or one goristro.
A summoned demon appears in an unoccupied space within 60 feet of its summoner, acts as an ally of its summoner, and can't summon other demons. It remains for 1 minute, until it or its summoner dies, or until its summoner dismisses it as an action.
Quick Reference
Running This Encounter
A Balor is a terrifying demon lord that demands respect and tactical positioning. Use its massive 15-foot reach and legendary actions to control the battlefield, forcing the party to constantly adapt their positioning. The Balor should lead with its most devastating attacks—Death Ward, Fire Storm, and its whip—to quickly eliminate threats or force concentration saves. Remember that it regenerates 10 HP per turn, making burst damage and resource management critical for the party's success.
Combat Tactics
The Balor uses its whip to grapple and pull enemies into melee range, then unleashes devastating melee attacks with its longsword. It casts Death Ward preemptively and uses Fire Storm when enemies cluster together, prioritizing spellcasters who can threaten its concentration.
Environment & Setting
An infernal temple, a demon lord's lair deep underground, or a planar rift crackling with eldritch energy. The arena should feature difficult terrain, pillars for cover, and perhaps lava or magical hazards to reinforce the demonic setting.