Calamity Beshaba

Generate Chaos (Recharge 1d10). If Calamity Beshaba is hit by a spell from an enemy, she causes a Wild Magic Surge to happen (See Wild Magic table,PHB).

Choas Aura (Recharges after a Short or Long Rest). If Calamity Beshaba would be reduced to 0 hit points, her current hit point total instead resets to 500 hit points, she recharges her Chaos Aura, and she regains any expended uses of Legendary Resistance. Additionally, Calamity Beshaba can now use the options in the "Mythic Actions" section for 1 hour. 

Legendary Resistance (5/Day). If Calamity Beshaba fails a saving throw, she can choose to succeed instead.

Multiattack. Calamity Beshaba makes three attacks:  one with Reckoning Bite, one with Calamity Claw, and one with Devastating Tail.

Reckoning Bite. Melee Weapon Attack: +19 to hit, reach 20 ft., one target. Hit: 23 (2d12 + 10) piercing damage plus 19 (3d12) force damage.

Calamity Claw. Melee Weapon Attack: +19 to hit, reach 15 ft., one target. Hit: 21 (2d10 + 10) slashing damage. If the target is a Huge or smaller creature, it is grappled (escape DC 20) and is restrained until this grapple ends. Calamity Beshaba can only give them  grappled this way at a time.

Devastating Tail. Melee Weapon Attack: +19 to hit, reach 15 ft., one target. Hit: 23 (2d12 + 10) bludgeoning damage. If the target is a creature, it must succeed on a DC 25 Strength saving throw or be knocked prone.

Chaos Aura (Recharge 5–6). Calamity Beshaba spews a dark aura in a 300-foot cone. Each creature in that area must make a DC 25 Dexterity saving throw. On a failed save, the creature takes 71 (11d12) damage of a type of Calamity Beshaba's choosing choosing: necrotic, force, psychic, thunder, or acid. On a successful save, the creature takes half as much damage.

Action Surge: Calamity Beshaba can take one additional action during her turn. This refreshes on an even number on the die (D10)

Regenerative Healing: Calamity Beshaba has the ability to have some form of healing. She can be able to heal 3d12 hit points 1d20 times, per dawn. 

Generate Chaos (Recharge 1d10). If Calamity Beshaba is hit by a spell from an enemy, she causes a Wild Magic Surge to happen. Roll 1d100.

Calamity Beshaba 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 Calamity Beshaba regains spent legendary actions at the start of her turn.

Attack. Calamity Beshaba makes one Calamity Claw or Devastating Tail attack action.

Vengeful Bite (Costs 2 Actions). Calamity Beshaba makes one Reckoning Bite attack. If the attack hits a creature, the target must succeed on a DC 27 Wisdom saving throw or become frightened of Calamity Beshaba until the end of its next turn.

Generate Chaos (Recharge 1d10). If Calamity Beshaba is hit by a spell from an enemy, she causes a Wild Magic Surge to happen. Roll 1d100.

If Calamity Beshaba's Generate Chaos trait has activated in the last hour, she can use the options below as legendary actions.

Hurl Through Raging Choas (Costs 2 Actions). Calamity Beshaba targets a creature she is grappling. The creature must succeed on a DC 25 Charisma saving throw or take 44 (8d10) psychic damage and be banished to The Abyss or The Void (Calamity Beshaba chooses). At the start of Calamity Beshaba's next turn, the creature reappears in an unoccupied space within 10 feet of Calamity Beshaba.

Chaos Aura (Costs 3 Actions). Calamity Beshaba pulses with dark choatic energy. Each creature of Calamity Beshaba's choice in a 60-foot-radius sphere centered on her must make a DC 27 Dexterity saving throw. On a failed save, the creature takes 39 (6d12) damage of a type chosen by Calamity Beshaba: force, psychic, necrotic, thunder, or acid. On a successful save, the creature takes half as much damage.