Cocolia, Mother Of Deception

Immutable Form: Cocolia is immune to any shape-changing effects, as well as Cold, Psychic, and Radiant damage.

Heartless Touch: Cocolia's Cold and Radiant attacks have a chance to Stun the target for one turn. The targets must succeed on a CON save (DC varies) to avoid it. Only one save is required to avoid the effect, regardless of whether the attack deals multiple different damage types or not. The damage that requires a save is labeled after the attack, C for Cold and R for Radiant.

If the target fails the save on a Cold Damage attack, they are Frozen. Until the start of their next turn, they have vulnerability to Fire Damage. Their next turn is skipped.

If the target fails the save on a Radiant Damage attack, they are Imprisoned. In addition to the stun, they permanently move one spot back in the initiative order. If all hostile creatures are at the end of initiative order, Cocolia gains a second turn before they get a turn.

Legendary Resistance (4/Day). If Cocolia fails a saving throw, she may consume one resistance to instead pass the save, taking no damage even if she would normally take half.

Bone-Shattering Cold. Ranged Attack: +6 to hit, range 180 ft., 1 target. Hit: 24 (6d4 + 12) Cold damage. (DC 10, C)

Heartless Annihilator Call. Cocolia summons 2 Lances Of The Eternal Freeze within 20ft of her. Lances share her initiative, taking their turns right after she does. They have 30 HP and an AC of 10. When a Lance takes its turn, it deals 3d6 Cold Damage to hostile targets within 40 ft of it. (DC 5, C) While even a single Lance is on the field, her vulnerabilities become resistances. 

Harbinger Of Annihilation. Cocolia focuses on one target within 100 ft, entering the Charge state. Her next action will be spent using Soulrend Coldstream. While she is in the Charge state, she cannot move, as well as not being able to take actions or reactions.

Soulrend Coldstream. Cocolia fires off a massive storm of magic energy in the shape of ice shards bordering absolute zero. The target must pass a DC 18 DEX save, or take 16d6 Cold Damage, taking half on a success. Evasion does not help here. (DC 20, C)

Hoarfrost Of Eternal Isolation. Ranged Attack: +5 to hit, range 120 ft., 1 target. Hit: 22 (3d8 + 10) Cold damage. (DC 14, C)

Lance. When Cocolia is targeted by a melee attack that does not deal magical damage, she will target the attacker with the Bone-Shattering Cold.

Cocolia has no Legendary Actions. However, she has Legendary Traits. These unlock when she falls below 50% HP.

A Touch Of Pain. Cocolia's attacks that do not inflict Radiant Damage by default will now deal a bonus 4d6 Radiant Damage.

Stellaron's Might. Cocolia becomes immune to all status effects.

Fury Of The Eternal Freeze. Cocolia's Cold Damage attacks have their Frozen Save DC increased by 4.

After falling below 50% HP, Cocolia unlocks usage of her Mythic Actions. She has 3 Mythic Actions she may use at any time during another creature's turn, but she may use them on her own turn without consuming Mythic Actions. Any spent Mythic Actions regenerate at the start of her turn.

The Creation's Prelude. Cocolia enters the Charge state. Her next turn will be spent using Last Choir Of Genesis. While she is in the Charge state, she cannot move, as well as not being able to take actions or reactions.

Genesis Chord. Ranged Attack: +6 to hit, range 180 ft., 1 target. Hit: 24 (6d4 + 12) Cold damage and 24(6d4 + 12) Radiant Damage. (DC 16, R)

Last Choir Of Genesis. Cocolia conjures and drops a massive meteor of Radiant energy from the skies. All targets within 200 ft of her will take 24d10 Radiant Damage (DC 19, R)