Balthazar

Demonic Restoration. If the glabrezu dies outside the Abyss, its body dissolves into ichor, and it gains a new body instantly, reviving with all its Hit Points somewhere in the Abyss.

Magic Resistance. The glabrezu has Advantage on saving throws against spells and other magical effects.

Insatiable Greed. The Glaberzu can sense the presence of gold within 1,000 feet of itself. It can determine which location has the greatest amount of gold and can sense the direction to that site. If the gold is being moved, it knows the direction of the movement. It can't locate gold if any thickness of clay or lead, even a thin sheet, blocks a direct path between it and the gold.

Wishes. The Glaberzu has the Wish spell.The Glaberzu can cast it only on behalf of a non-fiend creature who communicates a wish in a way the glaberzu can understand. If the Glaberzu casts the spell for the creature, the Fiend suffers none of the spell's stress. Once the Fiend has cast it three times, the Fiend can't do so again for 365 days.

Multiattack. The glabrezu makes two Pincer attacks and uses Pummel or Spellcasting.

Pincer. Melee Attack Roll: +11, reach 10 ft. Hit: 16 (2d10 + 7) Slashing damage. If the target is a Medium or smaller creature, it has the Grappled condition (escape DC 17) from one of two pincers.

Pummel. Dexterity Saving Throw: DC 17, one creature Grappled by the glabrezu. Failure: 17 (3d6 + 7) Bludgeoning damage. Success: Half damage.

Spellcasting. The glabrezu casts one of the following spells, requiring no Material components and using Intelligence as the spellcasting ability (spell save DC 17):

At Will: Fog Cloud, Detect Magic, Dispel Magic, Command , Hold Person,Suggestion , Misty Step
1/Day Each: Confusion, Fly, Power Word Stun , Counterspell , Plane Shift , Crown of Madness

Storm of Crows (Recharge 6). The Glaberzu conjures a swarm of spectral crows and harpies in a 15-foot-radius sphere centered on a point the Demon can see within 120 feet of it. The sphere remains for 1 minute or until the demon loses concentration (as if concentrating on a spell), and its area is hightly obscured and difficult terrain.

Any creature that moves into the area for the first time on a turn or starts its turn there must make a DC 17 Constitution saving throw. A creature takes 10 (2d10) slashing damage plus 10 (2d10) psychic damage on a failed save.

Explosive Retribution. In response to dropping to 15 hit points or fewer, the glaberzu explodes. All other creatures within 30 feet of it must each make a DC 17 Dexterity saving throw, taking 9 [rollable](2d8) fire damage plus 9 [rollable](2d8) thunder damage on a failed save, or half as much damage on a successful one. 

Legendary Action Uses: 2. Immediately after another creature's turn, Balthazar can expend a use to take one of the following actions. Balthazar regains all expended uses at the start of each of their turns.

Pincer. Melee Attack Roll: +11, reach 10 ft. Hit: 16 (2d10 + 7) Slashing damage. If the target is a Medium or smaller creature, it has the Grappled condition (escape DC 17) from one of two pincers.

Spellcasting. The glabrezu casts one of the following spells, requiring no Material components and using Intelligence as the spellcasting ability (spell save DC 17):

At Will: Fog Cloud, Detect Magic, Dispel Magic, Command , Hold Person,Suggestion , Misty Step
1/Day Each: Confusion, Fly, Power Word Stun , Counterspell , Plane Shift , Crown of Madness