Black Monarch

Enraged. Once the Black Monarch falls bellow half HP it will enter an "Enraged Mode" in this mode it will create the "Black Hole" and change its attacks.

Spellcasting. The Black Monarch casts one of the following spells, requiring no Material components and using Wisdom as the spellcasting ability (spell save DC 19 to hit +10):
At Will: Arms of Hadar (2nd Level), Witch Bolt,  Frost Bite (5th level)

3 / Day: Counter Spell, Hex, Fear

2 / Day: Hunger of Hadar, Vampiric Touch, Blight

1 / Day: Mirror Image, Synaptic Static

Multiattack. The Black Monarch makes three attacks using Soul Chain Blade or Black Sphere in any combination.

Multiattack (Enraged). The Black Monarch makes three attacks using Claws or Black Sphere in any combination.

Soul Chain Blade. Melee Weapon Attack: +12 to hit, reach 10 ft. Hit: 22 (3d10 + 6) Slashing damage plus Hit: 10 (3d6) Necrotic damage.

Black Sphere. Ranged Spell Attack: +11 to hit, range 120 ft. Hit: 23 (4d8 + 5) Necrotic damage plus Hit: 7 (2d6) Cold damage.

Claws. Melee Weapon Attack: +6 to hit, reach 10 ft. Hit: 11 (2d10) Slashing damage plus Hit: 7 (2d6) Necrotic damage.

Black Hole (Enraged). The Black Monarch uses their Soul Chain Blade to create a 10ft radius sphere centered on a point within 90 feet of himself. Any creature besides the Black Monarch that ends its turn within 10 feet of the sphere must make a (DC 19) Streangth saving throw or take 11 (2d10) Force damage. failure the creature is sucked in to the closest point inside the sphere and is restrained. Any creature that begins its turn inside the Black hole takes  16 (3d10) Force damage. A creature may attempt to escape the Black Hole with a (DC 19) Athletics or Acrobatics check. The Black Monarch may move the Black hole up to 20 feet on his turn. Successful  take half damage. 

Flame Step. The Black Monarch creates a wall of black flames around themself allowing them to teleport to an unoccupied space within 30 feet of itself that it can see.

Obscuring Flame. As a Reaction the Black Monarch can Create a veil of black flames around themselves giving them a +6 bonus to their AC potentialy causing the attack to miss.

The Black Monrach has 3 Legendary actions (4 in Lair) 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. The Black Monarch regains spent legendary actions at the start of its turn.

Soul Chain Blade / Claws (Costs 1 Actions). The Black Monarch makes one Soul Chain Blade or Claws attack twords one creature.

Gravity Leap (Enraged) (Costs 2 Actions). The Black Monarch warps space around itself and teleports to an unnocupied space within 30 feet. Any creature that was next to it during the teleportation must make a DC 19 Dexterity saving throw or take 16 (3d10) Force Damage, on a sucess the creature takes no damage.

Gravity Cover (Enraged) (Cost 2 Actions). The Black Monarch teleports into the center of the black hole giving themselves +5 AC. The Monarch cannot use this action until the start of their next turn.