Boss Encounter 3 - lvl 5 to 10

1x Glabrezu Large fiend (demon) , chaotic evil
Armor Class 17 (Natural Armor) Hit Points (15d10 + 75) Speed 40 ft.
STR 20 (+5) DEX 15 (+2) CON 21 (+5) INT 19 (+4) WIS 17 (+3) CHA 16 (+3)
Saving Throws STR +9, CON +9, WIS +7, CHA +7 Damage Resistances Cold, Fire, Lightning; Bludgeoning, Piercing, and Slashing from Nonmagical Attacks Damage Immunities Poison Condition Immunities Poisoned Senses Truesight 120 ft., Passive Perception 13 Languages Abyssal, Telepathy 120 ft. Challenge 9 (5,000 XP) Proficiency Bonus +4
Innate Spellcasting. The glabrezu's spellcasting ability is Intelligence (spell save DC 16). The glabrezu can innately cast the following spells, requiring no material components:
At will: darkness, detect magic, dispel magic
1/day each: confusion, fly, power word stun
Magic Resistance. The glabrezu has advantage on saving throws against spells and other magical effects.
Actions Multiattack. The glabrezu makes four attacks: two with its pincers and two with its fists. Alternatively, it makes two attacks with its pincers and casts one spell.
Pincer. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: (2d10 + 5) bludgeoning damage. If the target is a Medium or smaller creature, it is grappled (escape DC 15). The glabrezu has two pincers, each of which can grapple only one target.
Fist. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: (2d4 + 2) bludgeoning damage.