Cult of Chaos Elite

One with the darkness. Most dark based magics will do half or no damage to this creature or have no effect such as maddness, chaos, or Emotion magic

Spellcasting. The Cult of Chaos Elite is a Powerful spellcaster. Its spellcasting ability is 15 (spell save DC 15, +6 to hit with spell attacks). The Cult of Chaos Elite has following spells prepared:
Cantrips (at will): Decompose, Message 
1st level (8 slots): Cause Fear, Command, Detect magic, Arms of Hadar

2nd level (5 slots): Alter slef, Cloud of daggers, Pass without a trace

3rd level (3 slots): Bestow curse, Counterspell, Dispel magic

4th level (2 slots): Blight

Sacrificial ritual. With no less than up to four Elite cultists of chaos the Cult of Chaos Elite may give up it's own life along with all others participating in the ritual to summon a beast of pure darkness/Evil.

Dark whip. Melee Weapon Attack: +6 to hit, reach 5 ft., 1 or 2 targets. Hit: 12 2d8 +4 Necrotic (or dark) damage. two black tendrils appear from the Cult of Chaos Elite's back and lash out at one or two targets. Each tendril does the described damage above.

Ink of dispair. RangedWeapon Attack: +6 to hit, range 20/90 ft., up to 6 targets. Hit: 8 (2d6 + 2) Necrotic damage. A black ball of sludge (ink) forms in front of the Cult of Chaos Elite's hand. Six thin streaks of ink then fire out towards target creature(s) directly striking them wherever they may stand.

Shadow shift. As a bonus action the Cult of Chaos Elite melds into an inky black circle of darkness which appears on the ground and can move double it's movement speed, while the Cult of Chaos Elite is moving creatures who arent blinded can see a trail of inky blackness on the ground following the current location of the cultist. the cultist then reappears at the location it has moved to. This has the same effect as both the dash and disengage action combined.

Clutches of darkness. If the Cult of Chaos Elite is given an opportunity attack it may attempt to grapple a creature with a large pair of jaws made of dark mana. Target creature must succeede on a strength saving throw of equal DC to the Cult of Chaos Elite's spell save DC.