Asmodeus

Fiendish Regeneration. Asmodeus regains 50 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. Asmodeus dies only if he starts his turn with 0 hit points and doesn’t regenerate. If Asmodeus dies, his body regenerates, returning to life 13 (2d12) days later.

Hellfire. Asmodeus' attacks ignore resistance to fire and necrotic damage.

Legendary Resistance (5/Day). If Asmodeus fails a saving throw, he can choose to succeed instead.

Limited Magic Immunity. Asmodeus can't be affected or detected by spells of 6th level or lower unless he wishes to be. Asmodeus has advantage on saving throws against all other spells and magical effects.

Submission Aura. When a creature moves to be within 120 feet of Asmodeus, they must succeed on a DC 24 Wisdom saving throw or have the Frightened condition. While Frightened, creatures kneel before Asmodeus, taking no actions unless he commands otherwise. If Asmodeus deals damage to a kneeling creature, the creature’s Frightened condition ends. A creature that succeeds the saving throw is immune to this effect for 1 hour.

Multiattack. Asmodeus makes four attacks.

Flaming Sword. Melee Weapon Attack: +19 to hit, reach 15 ft., one target. Hit: 29 (3d12 + 10) necrotic damage plus 14 (4d6) fire damage. The target's hit point maximum is reduced by an amount equal to the damage taken.

Ruby Ray. Ranged Spell Attack: +19 to hit, range 300 ft., one target. Hit: 43 (6d10 + 10) radiant damage, and the next attack the target makes has disadvantage.

Fires of the Nine Hells (Recharge 5–6). Asmodeus chooses a point he can see within 500 feet of him, which explodes into a roaring inferno. All creatures within a 60-foot-radius sphere centered on that point must make a DC 24 Dexterity saving throw, taking 70 (20d6) fire damage and 70 (20d6) necrotic damage on a failed save, or half as much damage on a successful one. Creatures that fail the save and objects that aren't being worn or carried begin Burning.

Spellcasting. Asmodeus casts one of the following spells, requiring no material components and using Wisdom as the spellcasting ability (spell save DC 27):

At will: Command (5th level), Darkness, Invisibility

1/day each: Antimagic Field, Mass Heal, Sunburst, Wish

Misdirection (Recharges after a Short or Long Rest). Asmodeus creates up to four illusory duplicates within 120 feet of him. The duplicates are intangible and don’t occupy their space. They lasts for 1 minute, but end early if Asmodeus dismiss them (no action required) or has the Incapacitated condition. Asmodeus can cast spells and abilities from any of the duplicates' space, and has advantage on attacks against a creature within 5 feet of a duplicate. Asmodeus can move any number of duplicates up to 50 feet as a bonus action on subsequent turns.

Asmodeus 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. Asmodeus regains spent legendary actions at the start of his turn.

Attack. Asmodeus makes one Flaming Sword or Ruby Ray attack.

Cast Spell. Asmodeus uses Spellcasting.

Hellish Smite. Asmodeus targets a creature he can see within 300 feet of him, calling down a bolt of hellish lightning. The target must make a DC 24 Dexterity saving throw, taking 21 (6d6) lightning damage plus 21 (6d6) fire damage on a failed save, or half as much damage on a successful one.

Teleport. Asmodeus magically switches positions with one of his duplicates.

Infernal Word (Costs 2 Actions). Asmodeus forces one creature he can see within 120 feet to make a DC 24 Intelligence saving throw, taking 45 (10d8) force damage on a failed save, or half as much damage on a successful one. A creature that fails the save is Stunned for up to 1 minute. The Stunned creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Hell-Lord’s Suggestion (Costs 3 Actions). Asmodeus forces one creature he can see within 60 feet to make a DC 24 Charisma saving throw, taking 44 (8d10) psychic damage and being Charmed on a failed save, or half as much damage and no additional effect on a success. While Charmed, a creature is under Asmodeus’s control and obeys his commands to the best of its ability. At the end of each of its turns, a Charmed target can repeat the saving throw, ending the effect on a success, but taking the damage again on a failed save.

Summon Underling (Costs 3 Actions). Asmodeus summons any Devil of CR 20 or less in an unoccupied space he can see. The summoned fiend remains until destroyed or until Asmodeus dismisses it as a bonus action. Asmodeus can have no more than five fiends summoned in this way at a time.