Alton, Ascendant

Divine Being. Alton can’t be surprised and can’t be changed into another form against his will.

Innate Spellcasting. Alton’s innate spellcasting ability is Charisma (spell save DC 21, +13 to hit with spell attacks). He can innately cast the following spells, requiring no material components:

At will: chromatic orb (cold orb only; see “Actions” below), detect magic, misty step

2/day each: control weather, detect thoughts, ice storm

Legendary Resistance (5/Day). If Alton fails a saving throw, he can choose to succeed instead.

Frigid Aura. So long as Alton has at least 1 hit point and at most 100 hit points, each creature within 10 feet of him takes 10 cold damage at the start of each of his turns.

Magic Resistance. Alton has advantage on saving throws against spells and other magical effects.

Unusual Nature. Alton doesn’t require air, food, drink, or sleep.

Multiattack. Alton attacks twice with his Alorin sword or with three quintessence darts or with two polar rays, or some combonation such that doesn't exceed two attacks.

Alorin Sword. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) piercing damage plus 9 (2d8) cold damage plus 3(1d6) psychic damage.

Touch of Frost. Melee Spell Attack: +13 to hit, reach 5 ft., one creature. Hit: 13 (3d8) cold damage, and the target can’t take reactions until the start of its next turn.

Chromatic Orb. Ranged Spell Attack: +13 to hit, range 90 ft., one creature. Hit: 13 (3d8) cold damage.

Quintessence Dart. Ranged Weapon Attack: +7 to hit, range 20/60 ft., one target. Hit: 5 (1d4 + 3) piercing damage plus 3 (1d6) psychic damage.

Cone of Nightmares (Recharges after a Short or Long Rest). Alton causes a magical blast of cold air to erupt from his hand. Each creature in a 60-foot cone must make a DC 21 Constitution saving throw, taking 36 (8d8) cold and psychic damage on a failed save, or half as much damage on a successful one.

Create Ice Mephit (3/Day).Alton reaches forth and forms quintessence in an unoccupied space he can see within 20 feet, where it magically transforms into an ice mephit (see its entry in the Monster Manual). The mephit acts immediately after Alton in the initiative order and obeys his commands.

Stasis (Recharge 5–6). Alton creates a freezing pocket dimension, contained within a cube that hovers in a space within 5 feet of himself. Alton then targets a creature he can see within 60 feet of the cube. The target must succeed on a DC 21 Charisma saving throw or become trapped in the cube, which is immovable. If the saving throw succeeds, the cube shatters and nothing else happens. A creature trapped in the crystal is stunned, has total cover against attacks and other effects outside the crystal, and takes 21 (6d6) cold damage at the start of each of its turns. The creature can repeat the saving throw at the end of each of its turns, freeing itself on a success. The creature is also freed if the cube is destroyed, which is a Tiny object with AC 18, 9 hit points, and immunity to all damage except fire damage and radiant damage. The freed creature appears in an unoccupied space of its choice within 30 feet of the shattered cube.

Polar Ray. Ranged Spell Attack: +13 to hit, range 120 ft., one target. Hit: 14 (4d6) cold damage.

Blizzard Veil. Alton creates a magical blizzard in a 30-foot-radius sphere centered on himself. The area within the sphere is heavily obscured, and the sphere moves with Alton. The effect lasts until Alton drops to 0 hit points in this form, until he chooses to end the effect (no action required), or until his concentration is broken (as if concentrating on a spell).

Alton can take 4 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 turn. Alton regains spent legendary actions at the start of her turn.

Alorin Sword. Alton attacks once with his Alorin Sword.

Polar Ray. Alton uses Polar Ray.

Teleport. Alton teleports to an unoccupied space he can see within 60 feet. (1/round)

Intensify Aura (Costs 2 Actions). Alton’s Frigid Aura deals an extra 10 cold damage until the end of his next turn.

Blinding Gleam (Costs 2 Actions). Alton’s form flares with a blue light. Each creature that can see Alton and is within 10 feet of her must succeed on a DC 17 Wisdom saving throw or be blinded by Alton’s magical gleam for 1 minute. The blinded creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Touch of Frost (Costs 2 Actions). Alton uses Touch of Frost.

Ice Flurry (Costs 2 Actions). Each creature within 30 feet of Alton takes 5 (2d4) piercing damage from swirling ice, and nonmagical, open flames in that area are extinguished.

Splinter (Costs 3 Actions). Alton uses Create Ice Mephit or causes one to ice mephit he can see within 60 feet of himself to explode and die. A mephit that dies in this way does not use its Death Burst. Instead, each creature within 10 feet of the exploding mephit must succeed on a DC 21 Dexterity saving throw, taking 13 (3d8) piercing damage on a failed saving throw, and half as much damage on a successful one.