Mephistopheles, Lord of the Eighth

Mephistopheles large fiend (devil, wizard), lawful evil

Armor Class 23 (natural armor)

Hit Points 550 (50d10 + 250)

Speed 40 ft., fly 80 ft.

STR 22/+6

DEX 17/+3

CON 21/+5

INT 30/+10

WIS 20/+5

CHA 22/+6

Saving Throws CON +14, CHA +15, WIS +14

Skills Arcana +28, Persuasion +15, Perception +14, Nature +19

Damage Resistances Bludgeoning, Piercing, and Slashing from Nonmagical Attacks that aren't Silvered

Damage Immunities Fire, Cold, Poison

Condition Immunities Poisoned, Charmed, Frightened, Exhaustion

Senses Truesight 120 ft., Darkvision 120 ft., Passive Perception 24

Languages All languages, Telepathy 120 ft.

Proficiency Bonus +9

Devil's Sight. Magical darkness doesn't impede the devil's darkvision.

Magic Resistance. The devil has advantage on saving throws against spells and other magical effects.

Regeneration. Mephistopheles regains 40 hit points at the start of his turn. If he takes radiant damage this feature doesn’t work for a round. He can only die if he starts his turn with 0 hit points and can’t regenerate.

Hellfire Mastery. Mephistopheles has such control over the flames of Hell that his fire damage ignores fire resistance of every creature.

Legendary Resistance (4/day). If Mephistopheles fails a saving throw, he can choose to succeed instead.

Fear Aura. Any creature that’s not a devil and behind full cover that can see Mephistopheles needs to make a DC 23 Wisdom save or be frightened by the archdevil for 1 hour. Creatures can remake the save at the end of their turns, gaining immunity to the effect for 24 hours on a success. 

Actions

• Multiattack. Mephistopheles makes two attacks with his Ranseur and then uses Hurl Fire. Or he can use Spellcasting and then a Hurl Flame attack.
• Hurl Flame. Ranged Spell Attack: +19 to hit, range 150 ft., two targets. Hit: 19 (3d12) fire damage. If the target is a flammable object that isn't being worn or carried, it also catches fire.
• Ranseur +3. Melee Weapon Attack: +18 to hit, reach 10 ft., one target. Hit: 18 (2d8 + 9) piercing damage and 20 (4d10) fire, cold, or lightning damage, his choice.
• Spellcasting. Mephistopheles uses Intelligence as his spellcasting ability (DC 27, +19 to hit). He casts the following spells with his ranseur as his spellcasting focus.
• At will: detect magic, identify, alter self (can become Medium sized), shield, counterspell, bestow curse, fireball, lightning bolt (5th level)
• 5/day each: fabricate, wall of ice, wall of fire, dimension door, cone of cold
• 3/day each: chain lightning, firestorm, dispel evil and good, raise dead
• 1/day each: meteor swarm, forbiddance
• Teleportation. The Lord of the Eighth and anything he’s carrying (not including creatures) magically teleports up to 120-feet.

Legendary Actions

Mephistopheles can take up to 4 Legendary Actions per round but only after another creature’s turn. All spent Legendary Actions return at the beginning of his turn.

Teleport. Mephistopheles uses his Teleportation

Hellfire Body (2 Actions). The Lord of the Eighth’s body erupts with flame and persistently burns! Every creature within 10 ft.  Mephistopheles and not behind full cover must make a DC 23 Dexterity save or take 10 (3d6) fire damage. Then anyone who hits him with a melee attack within 10 ft. takes 10 (3d6) fire damage once per turn. This affect ends at the end of his next turn.

Ice Storm (2 Actions). Mephistopheles causes freezing rain and sleet fall in a 20-foot-tall cylinder with a 40-foot radius centered on a point within 150-feet. The area is heavily obscured, and exposed flames in the area are doused. The ground in the area is covered with slick ice, making it difficult terrain. When a creature enters the spell's area for the first time on a turn or starts its turn there, it must make a DC 23 Dexterity saving throw. On a failed save, it falls prone. If a creature starts its turn in the spell's area and is concentrating on a spell, the creature must make a DC 23 Constitution saving throw or lose concentration. This effect ends at the beginning of his turn.

Hurl Flame. Mephistopheles uses his Hurl Flame attack