Armor Class 17
Hit Points 189 (18d10 + 90)
Speed 30 ft., fly 30 ft.
Saving Throws CON +9, INT +10, WIS +8, CHA +7
Skills Arcana +10, History +10, Perception +8
Damage Resistances cold
Damage Immunities fire, poison
Condition Immunities poisoned
Senses Darkvision 120 ft., passive Perception 18
Languages Infernal; telepathy 120 ft.
Challenge 12
Diabolical Restoration. If the devil dies outside the Nine Hells, its body disappears in sulfurous smoke, and it gains a new body instantly, reviving with all its Hit Points somewhere in the Nine Hells.
Magic Resistance. The devil has Advantage on saving throws against spells and other magical effects.
Multiattack. The devil makes two Thundering Halberd attacks.
Thundering Halberd. m +9, reach 10 ft. Hit: 16 (2d10 + 5) Slashing damage plus 14 (4d6) Thunder damage.
Utterance of Pain. wis DC 18, each creature in a 20-foot Emanation originating from the devil. The target has the Stunned condition until the end of the devil's next turn.
Utterance of Unmaking. con DC 18, each creature in a 20-foot Emanation originating from the devil. 22 (4d10) Force damage. Half damage.
ABH, p. 17