Devil’s Sight. Magical darkness doesn’t impede Belial’s darkvision.
Fear aura. Any creature hostile to Belial that starts its turn within 20ft of Belial must make a DC 26 Wisdom saving throw, unless Belial is incapacitated. On a failed save, the creature is frightened until the start of its next turn. If a creature's saving throw is successful, the creature is immune to Belial's Fear Aura for the next 24 hours.
Fiery Weapons. Belial’s weapon attacks are magical. When he hits with any weapon, the weapon deals an extra 33 (6d10) fire damage (included in the weapon attacks below).
Innate Spellcasting. Belial's innate spellcasting ability is Charisma (spell save DC 26). He can innately cast the following spells, requiring no material components:
At will: alter self (can become Medium when changing his appearance), detect evil and good, fireball, invisibility (self only), wall of fire
3/day each: blade barrier, dispel evil and good, finger of death
Legendary Resistance (5/Day). If Belial fails a saving throw, he can choose to succeed instead.
Magic Resistance. Belial has advantage on saving throws against spells and other magical effects.
Regeneration. Belial regains 20 hit points at the start of her turn. If he takes radiant damage, this trait doesn’t function at the start of his next turn. Belial dies only if he starts his turn with 0 hit points and doesn’t regenerate.
Multiattack. Belial can attack up to three times with his Great sword or attack with his Great sword once and use Horrid Touch or Teleport.
Great sword. Melee Weapon Attack: +18 to hit, reach 15 ft., one target. Hit: 22 (2d10 + 10) Slicing damage plus 33 (6d10) fire damage.
Horrid Touch (Recharge 5–6).Belial touches one creature within 15 feet of him. The target must succeed on a DC 26 Constitution saving throw or take 52 (8d12) necrotic damage and be poisoned for 2 minutes. While poisoned in this way, the target is also blinded and deafened. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
Teleport. Belial magically teleports, along with any equipment he is wearing or carrying, up to 120 feet to an unoccupied space he can see.
Summon Devil (3/Day). Belial chooses what to summon. All Summon Devil casts can be used simultaneously.
Belial can summon 1d10 Bearded Devil or 1d10 Shadow Demon or 1d8 Barbed Devil or 1d8 Barlgura or 1 Pit Fiend.
A summoned devil appears in an unoccupied space within 60 feet of Belial, acts as an ally of Belial, and can’t summon other devils. It remains for 1 minute, until it or Belial dies, or until Belial dismisses it as an action.
Belial can take 5 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn. Belial regains spent legendary actions at the start of his turn.
Teleport (Costs 1 Action). Belial uses his Teleport action.
Immolating Gaze (Costs 2 Actions). Belial turns his magical gaze toward one creature he can see within 120 feet of him and commands it to combust. The target must succeed on a DC 28 Wisdom saving throw or take 26 (4d12) fire damage.
Hellish Pain (Costs 3 Actions). Belial touches one creature adjacent to himself causing them to make a DC 25 Constitution saving throw or take 35 (10d6) psychic damage and be stunned until the end of their next turn.