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