Xardorok Sunblight (Boss)

Duergar Resilience. Xardorok has advantage on saving throws against poison, spells, and illusions, as well as to resist being charmed or paralyzed.

Innate Spellcasting. Xardorok’s innate spellcasting ability is Charisma (spell save DC 15, +7 to hit with spell attacks). He can innately cast the following spells, requiring no material components:

At will: eldritch blast (see “Actions” below), mage hand

1/day each: hold person, suggestion, hunger of hadar, summon greater demon

Sunlight Sensitivity. While in sunlight, Xardorok has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.

Multiattack. Xardorok can make three attacks, twice with a weapon and once by casting eldritch blast. Xardorok can replace a weapon attack for another eldritch blast

Spiked Gauntlet. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 5 (1d4 + 3) piercing damage and  (2d8) Psychic damage, or 8 (2d4 + 3) piercing damage and  (2d8) Psychic damage, while Xardorok is enlarged.

Eldritch Blast (Cantrip). Ranged Spell Attack: +7 to hit, range 120 ft., one creature. Hit: 9 (1d10 + 4) force damage.

Enlarge (Recharges after a Short or Long Rest). For 1 minute, Xardorok magically increases in size, along with anything he is wearing or carrying. While enlarged, Xardorok is Large, doubles his damage dice on Strength-based weapon attacks (included in his attacks), and makes Strength checks and Strength saving throws with advantage. If Xardorok lacks the room to become Large, he attains the maximum size possible in the space available.

Invisibility (Recharge 4–6). Xardorok magically turns invisible until he attacks, he casts a spell, he uses his Enlarge, or his concentration is broken (as if concentrating on a spell). Any equipment Xardorok wears or carries is invisible with him.

Command Mindflayer as a bonus action, Xardorok can direct his pet to attempt to grapple and consume a target

Hellish Rebuke (2/Day). When Xardorok is damaged by a creature within 60 feet of him that he can see, the creature that damaged him is engulfed in hellish flames and must make a DC 15 Dexterity saving throw, taking 16 (3d10) fire damage on a failed save, or half as much damage on a successful one.

Counterspell (3/day). You attempt to interrupt a creature in the process of casting a spell. If the creature is casting a spell of 3rd level or lower, its spell fails and has no effect. If it is casting a spell of 4th level or higher, make an ability check using your spellcasting ability. The DC equals 10 + the spell's level. On a success, the creature's spell fails and has no effect.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the interrupted spell has no effect if its level is less than or equal to the level of the spell slot you used.

Xardorok can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn. Xardorok regains spent legendary actions at the start of its turn.

Command ally. Xardorok targets one ally it can see within 30 feet of it. If the target can see and hear Xardorok, the target can make one weapon attack as a reaction and gains advantage on the attack roll.

Weapon Attack. Xardorok makes a  single weapon attack

Frighten Foe (Costs 2 Actions). Xardorok targets one enemy it can see within 30 feet of it. If the target can see and hear it, the target must succeed on a DC 16 Wisdom saving throw or be frightened until the end Xardorok's next turn.