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.

Spellcasting. The devil casts one of the following spells, requiring no Material components and using Intelligence as the spellcasting ability (spell save DC 18):

At will: Detect Magic, Detect Thoughts

2/day each: Dimension Door, Modify Memory

Multiattack. The devil makes two Thundering Halberd attacks.

Thundering Halberd. Melee Attack Roll: +9, reach 10 ft. Hit:16 (2d10 + 5) Slashing damage plus 14 (4d6) Thunder damage.

Utterance of Pain. Wisdom Saving Throw: DC 18, each creature in a 20-foot Emanation originating from the devil. Failure: The target has the Stunned condition until the end of the devil's next turn.

Utterance of Unmaking. Constitution Saving Throw: DC 18, each creature in a 20-foot Emanation originating from the devil. Failure: 22 (4d10) Force damage. Success: Half damage.