Magic Resist EX. The being called Abnuul has advantage on saving throws against spells and magical effects, If user succeeds, the spell or magical effect is unable to be used again for 1d6 turns. (up to 3 spells/magical effects at once)

Spellcasting. The [Abnuul is a 20tg-evel spellcaster. Its spellcasting ability is Intellegience (spell save DC 23, +15 to hit with spell attacks). The being known as Abnuul has all following Wizars, Warlock, Druid spells prepared:
Cantrips (at will): Fire Bolt, Control Flames, Encode Thought, Prestidigitation, Ray of Frost, 
1st level (5 slots): Absorb Elements, Command, Detect Magic, Mage Armor, Magic Missle, Shield 

2nd Level (5 slots): Calm Emotions, Darkness, Enlarge/Reduce, Mirror Image, Shatter

3rd Level (4 slots): Bestow Curse, Counterspell, Dispel Magic

4th Level (4 slots): Banishment, Blight, Dimension Door, Fabricate, Ice Storm

5th level (3 slots): Cone of Cold, Conjure Elemental, Scrying, 

6th level (3 slots): Circle of Death, Chain Lightning

7th level (3 slots): Finger of Death, Plane Shift, Resurrection

8th level (2 Slots): Clone, Dominate Monster

9th level (2 slots):Meteor Swarm, Power Word Kill, Psychic Scream

Chain of Reality: Abnuul wields 4 chains, for which each chain has the ability to enact and protect Abnuul, meaning the max amount of actions for Abnuul in total is 5. Each chain has 385 HP and has an AC of 30

Chain of Destruction. Melee Weapon Attack: +15 to hit, reach 10 ft., 1 target. Hit: 30 (4d10 + 7) Force damage. The target must succeed on a DC 23 Strength saving throw or be pushed away 20 feet and knocked prone.

Chain of Nullification. Melee Weapon Attack: +15 to hit, range 10 ft., 1 target. Hit: 30 (4d10 + 7) Force Damage. The target must succeed on a DC 23 Intelligence saving throw, or all spells and magical effects currently affecting them is dispelled

Chain of Damnation. Melee Weapon Attack: +15 to hit, range 10 ft., 1 target. Hit: 30 (4d10 + 7) Necrotic Damage. The target must succeed on a DC 23 Constitution Saving throw or its hit points maximum is reduced by am amount equal to the damage taken. This reduction lasts only until the afflicted makes a long rest

Chain of Hellfire. Melee Weapon Attack: +15 to hit, range 10 ft., 1 target. Hit 30 (4d10 + 7) Fire damage. The target must make a DC 23 dexterity saving throw taking 45 (10d8) fire damage on a failed save, take half as much damage on a successful one

Chained Recoil. Any time when one of Abnuul's chains are struck, he can cast any spell at will, as a reaction (Going up to 5th Level).

Chain Armor If the chains, are still alive and Abnuul is reduced below 25% max hp. For which will cause him to be wrapped up by all of his current alive chains- for which each chain around him heal him by 5d12, plus give him 5 AC.

Damnation Pulse (Chain of Damnation): If the Chain of Damnation is struck by anything radiant, Necrotic, or force based, they can blast a shockwave forward in a 50 ft arc, for which if they are struck by this, they get knocked back 30 ft, and knocked prone.

Chain's of Reality EX: Instead of Abnuul having the use of these- His chains instead do, but if a chain uses a legendary action, the rest can't act for that turn.

Legendary Resist (3/day) If Abnuul or one of his chain's fail a saving throw, he can choose to succeed instead

Eternal Damnation Whiplash (Costs 4 Actions). The Chain of Damnation will power up for 3 turns, gaining 500 temp HP.  If the TEMP HP is not depleted within 3 turns, All within 15 ft, must make a Dex saving throw of a DC 23. If on a failed throw, the target takes 12d12 necrotic damage that can't be reacted to, and lose maximum HP equal to damage taken. If successful, Take half dmg only

Sinful Hellfire Coil: (Costs 4 Actions). The Chain of Hellfire can coil around 1 target- and that target must make a Strength Saving throw of a DC 23. If failed, they are now Restrained for 1d4 turns, unable to heal or be healed for twice that many turns, and take 15d8 Fire damage. If on a successful save, you avoid the effects of this move.

Energy Destruction Burst: (Costs 4 actions) The Chain of Destruction is able to remove any projectile or energy, regarding it magical, non magical, living, non living, and destroys it, erasing it from reality within 5 ft of it.