Airisted Ascended

Spellcasting. Airisted casts one of the following spells, requiring no material components and using Intelligence as the spellcasting ability (spell save DC 22):

At will: animate dead (as an action), detect magic, dispel magic, Telekinesis, lightning bolt, mage hand, prestidigitation, Blite, Bane, Curse

2/day each: dimension door, invisibility, scrying (as an action)
1/day each: dominate monster, globe of invulnerability, plane shift (self only).

Damage Resistances cold, lightning, Fire, Thunder. 
Damage Immunities poison; bludgeoning, piercing, and slashing from nonmagical attacks, necrotic
Condition Immunities charmed, exhaustion, frightened, paralyzed, poisoned, stunned

Airisted can take up to 2 actions per turn.

Scales of Ma’at: Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 7 (1d8 + 5) Blogoning damage plus 9 (2d8) necrotic damage. A creature must make a constitution saving throw. if failed the target will take an additional 1d6 necrotic damage when hit by any attack or if is affected by any spell until the end of Airisted next turn

Flight of the Damned (Recharge 5–6). Airisted  conjures a torrent of flying, spectral entities that fill a 120-foot cone and pass through all creatures in that area before dissipating. Each creature in that area must make a DC 22 Constitution saving throw. On a failed save, the creature takes 36 (8d8) necrotic damage and is frightened of Airisted  for 1 turn. On a successful save, the creature takes half as much damage and isn't frightened. 

Vile Teleport. Airisted teleports, along with any equipment he is wearing or carrying, up to 30 feet to an unoccupied space he can see. He can cause each creature of his choice within 15 feet of his destination space to take a dex saving throw (DC 18) or take 10 (3d6) psychic damage. If at least one creature takes this damage, Vecna regains 80 hit points.

Airisted can take up to three reactions per round but only one per turn.

Dread Counterspell. Airisted utters a dread word to interrupt a creature he can see that is casting a spell. If the spell is 4th level or lower, it fails and has no effect. If the spell is 5th level or higher, Airisted makes an Intelligence check (DC 12 + the spell's level). On a success, the spell fails and has no effect. Whatever the spell's level, the caster takes 10 (3d6) psychic damage if the spell fails.

Fell Rebuke. In response to being hit by a non-magical attack, Airisted utters a fell word, dealing 10 (3d6) necrotic damage to the attacker, and teleports, along with any equipment he is wearing or carrying, up to 30 feet to an unoccupied space he can see

Legendary Reaction (3/Day). If Airisted fails a saving throw, he can choose to succeed instead.

Legendary Action: (1 per turn). Soul Collection if something with a soul dies within 120 feet of Airisted. he can consume the soul to immediately cast another spell or recharge Flight of the Damned, a soul consumed cannot be used for animate dead or be revived. 

Legendary Action: (Recharge 5-6). Command a Soul: Command a soul to be pulled from a living target within 120 feet that Airisted can see. The target must make a wisdom saving throw (DC 18) or fall uncourteous. the soul levitates above the body for 3 of their turns after 3 turns the soul is turned into a spirit that fights for Airisted taking its turn right after Airisted or can be used to power Soul Collection

Soul Diversion: if the soul of Airisted is not captured or distorted when he dies he can move his soul into another creature or object. If the creature is not dead the target must make a wisdom saving throw (DC 20) on failed the target it taken and is now considered Airisted using the creatures' stats and abilities but also has all of Airisteds legendary and mythic actions (if any actions are on cooldown they are reset). At the beginning of Airisteds turn and at the start of the targets turn (if the target was living) the target makes a wisdom saving throw (DC 20) on failed Airisted continues to possess the target on success the target pushes Airisted from there body leaving his soul vulnerable till the start of his next turn. 

While not in a body Airisteds soul uses the following stat block:

Large Undead (Spirit), Lawful Evil AC 22 (Ethereal Form) HP 150 (24d10) Speed 0 ft., fly 60 ft. (hover) Saving Throws INT +9, WIS +9, CHA +9 Skills Arcana +9, Insight +9, Perception +9

Damage Resistances : resistant to all damage types other than radiant, necrotic or poison

Damage Immunities necrotic, poison 

Condition Immunities charmed, paralyzed, prone

Senses Truesight 120 ft., Passive Perception 19

Ethereal Form. Airisted’s Soul can move through creatures and objects as if they were difficult terrain

2 Actions per turn, 1 Reaction per round

Soul Lash. Melee Spell Attack: +13 to hit, reach 10 ft., one target. Hit: 22 (4d8 + 4) psychic damage and the target must succeed on a DC 20 Intelligence saving throw or be stunned until the end of its next turn.

Soul Anchor. If a creature within 120 ft. dies or falls uncountious, Airisted may use a reaction to attempt possession (see Soul Diversion).

Mythic Vulnerability. If exposed outside a host, Airisted’s Soul takes double damage from radiant sources and cannot regain hit points. Airisted’s Soul heals 3d6 for of his turns his soul is in a body.