Ascendant Cerion updated

Legendary Resistance (5/Day). When the Ascendants fail a saving throw they can choose to succeed instead.

Unbreakable. Cerion has advantage on saving throws against spells and magical effects, additionally he has advantage on concentration saving throws.

Cold- and Radiant-Stance. At the beginning of each of this turns, Cerion changes his stance between Cold-Stance and Radiant-Stance.

Cold-Stance. While in the Cold-Stance, Cerion gains the following benefits:

Chilling Touch. Cerions spells and attacks that deal cold damage inflict one stack of Creeping Cold.

1 Stack = - 10 ft. movement speed
2 Stacks = disadvantage on Dexterity saving throws
3 Stacks = subtract 1d4 from attack rolls
4 Stacks = subtract 1d4 from saving throws
5 Stacks = Flash Freeze targets the creature besides the original target

Ice Cold. Cerion gains access to Flash Freeze, which he can use as a Bonus Action.

Radiant-Stance. While in Radiant Stance, Cerion gains the following benefits:

Sanctity. At the start of his turn, Cerion conjures a radiant blade 20 ft. above one pillar of his choice. At the start of his next turn the blade destroys the pillar.
Radiant Blade: 50 HP, AC 17, Immunities: Radiant, Necrotic, Poison, Psychic; Resistances: Fire; Vulnerabilites: Thunder

Judgement. Cerion gains access to Mark of Conviction, which he can use as a Bonus Action

Multiattack. Cerion makes 2 Attacks, she can replace one with his recharge ability or spellcasting.

Cold Burst (Ice-Stance). Melee or Ranged Attack Roll: +15, reach 5 ft. or range 150 ft. Hit: 4d6 + 8 Piercing damage and 3d8 Cold damage. Each hit reduces the targets movement speed by 5 feet, in addition to applying Creeping Cold stacks. 

Light Burst (Radiant-Stance). Melee or Ranged Attack Roll: +15, reach 5 ft. or range 150 ft. Hit: 3d8 + 8 Force Damage and 2d10 Radiant Damage. When a creature is hit by 2 Radiant Burst Attacks in one turn it must succeed a DC 21 Wisdom saving throw. Fail: The creature is blinded until the start of Cerions next turn.

Spellcasting. Cerion casts one of the following spells, using Intelligence as the spellcasting Ability (+15 to hit, spell save DC 21)

At Will: Detect Magic, Light, (C) Ice Knife (4th lvl version), (R) Spellfire Flare (4th lvl version), (C) Rime's Binding Ice (4th lvl version), Vortex Warp (4th lvl version)
2/Day Each: (C) Erupting Earth (4th lvl version, Cold instead of Bludgeoning damage), (R) Spellfire Storm, (C) Vitriolic Sphere (Cold instead of Acid damage), Flame Strike (Cold instead of Fire damage)
1/Day Each: (R) Wall of Light, (C) Wall of Ice

Frozen Verdict (Recharge 5-6). Cerion splits the room in half. One side is covered in ice, each enemy creature must succeed a DC 21 Strength saving throw. Fail: 10d6 Cold damage and the creatures movement speed is reduced to 0, until the end of their next turn. Success: Half damage and movement speed is reduced by 10 ft. until the end of their next turn. The other half is covered in radiant light, each enemy creature must succeed on a DC 21 Constitution saving throw. Fail: 10d6 Radiant damage and the creature is blinded until the end of their next turn. Success: Half damage and the creature subtracts 2 from all attack rolls until the end of their next turn.

Flash Freeze. Cerion targets one creature he can see within 120 ft. The creature is encased in an ice block, having the stunned and restrained condition. While in the ice block the creature is also vulnerable to Lightning damage.
Ice Block: 75 HP, AC 17, Immunites: Cold, Psychic, Poison; Resistances: Piercing, Lightning; Vulnerabilites: Bludgeoning, Fire

Mark of Conviction. Cerion marks a creature he can see within 120 ft. At the start of his next turn the mark explodes in a 10ft. Sphere around the creature, dealing 8d10 Radiant damage. For each allied creature, to the target in the Sphere, the damage is split evenly amongst them.

Reactive Weave. Cerion casts Counterspell in response to the spell's trigger, using the same spellcasting ability as Spellcasting

Legendary Action Uses: 4. Immediately after another creature’s turn, the Ascendants can expend a use to take one of the following actions. The Ascendants regains all expended uses at the start of each of Tarions turns.

Strike. One of the Ascendants makes one attack according to their current stance.

Cold Lightning (2 Actions). Cerion freezes one pillar. Larina targets a creature with a Tempest Strike. The creature must succeed on a DC 21 Dexterity saving throw. Fail: 6d6 Lightning damage and unable to take reactions until the end of their next turn. Success: Half damage only. If the creature was within 30 ft. of the frozen pillar, the lightning forks to all creatures within 30ft. of the pillar, forcing the same saving throw. The ice is then removed. If the lightning did not fork, the pillar gains 30 temporary Hit Points.

Shattering Winter (2 Actions). Cerion applies 1 stack of Creeping Cold onto a creature. Tarion then shatters all Creeping Cold stacks of a creature. Each creature within 15 ft. of the targeted creature must succeed a DC 21 Dexterity saving throw, the affected creature does the saving throw with disadvantage. Fail: 1d10 Piercing damage and 2d8 Cold damage for each stack of Creeping Cold shattered. Success: Half damage only.

Volcanic Pillar (2 Actions). Tarion summons one Earthen Pillar. Larina enhances it with fiery heat. This pillar is volcanic. An area 15 ft. around this pillar is treated as Difficult Terrain and in addition to its normal pulse damage, it deals 1d8 fire damage, scaling the same way as a normal Earthen Pillar.

Prison [once] (3 Actions). Tarion connects all active pillars through walls. Cerion freezes the walls. Larina electrifies them. Each wall between a pillar has the same statistics as an Earthen Pillar, but with 30 temporary Hit Points on top. A creature getting within 5 ft. of the wall must succeed on a DC 21 Constitution saving throw. Fail: 2d8 Cold damage and 2d8 lightning damage, additionally the creature's movement speed is reduced by half until the end of their next turn. Success: Half damage only. A creature can only be affected by this once per round, when ending its turn within 10 ft. of the wall or entering the area.