Aeol Cylva, Maestro of Swords and Song

Verdant Apotheosis (Mythic Trait: Recharges after a Short or Long Rest). If Aeol, The Lunar Song, Prince of Seasons is reduced to 0 hit points, he doesn’t die or fall unconscious. Instead his hit point maximum increases to 200, he regains 92 hit points, all legendary resistances, and gains 150 temporary hit points as vines, flowers, and fruit surround and protect him. In addition, he summons four awakened trees in unoccupied spaces within 15 feet of him. The awakened trees are under Aeol's control and act immediately after him in the initiative order. Additionally, Aeol can now use this statblock along with the options in the “Mythic Actions” section.

Of Song and Strife. Aeol is treated as if under the effects of Guardian of Nature and Investiture of Wind

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

Regeneration. Aeol regenerates 10 HP at the start of his turn while conscious.

Season's Greetings. When aeol uses a Song action, he can shift to a different seasonal aspect, and immediately use the song relating to that season at no action cost. 

• Fall - Song of Celerity
• Winter - Song of Security
• Spring - Song of Victory
• Summer - Song of Fury

Moonblade. While wielding the moonblade, spell attack rolls and saving throw DCs are increased by 1. Additionally, casting Shield does not cost a spell slot.

Innate Spellcasting. Aeol's spellcasting ability is Charisma (spell save DC 19, +11 to hit with spell attacks). He can innately cast the following spells with no material components:

At Will: booming blade, mind sliver, shield, Misty step

3/Day each: counterspell (as if 6th level), Greater Invisibility, fireball, Thunderwave (as if 3rd level), Dispel Magic (as if 6th level)

1/Day each: Destructive Wave, Greater restoration, Wall of Thorns, Harm, Power Word Pain

Multiattack. Aeol makes 2 attacks. He may cast a cantrip in place of one of these attacks.

Moonblade. Melee Weapon Attack: +12 to hit, reach 5 ft., one creature. Hit: 17 (1d8+12) slashing damage. Additionally, if Aeol rolls a 19 or a 20 on the d20 when attacking with the moonblade, it is a critical hit. If Aeol rolls a 20 on an attack roll with the moonblade, the target must succeed on a Constitution saving throw (DC 13), or lose their head.

Choir of Swords (Recharge 5-6). Aeol hits all creatures surrounding him in a 20 foot radius as if by Steel wind Strike. These attacks are made with advantage, and use the Moonblade's critical hit and vorpal properties. 

War Poet. Aeol is able to make use of Songs to enhance his abilities in combat. Aeol knows the following songs.

• Song of Celerity - Aeol casts a spell of 4th level of lower as a bonus action.
• Song of Security - The next time Aeol takes damage, he reduces it by 15
• Song of Victory - Aeol attempts to clear himself of any harmful conditions or spells as if by Dispel Magic. He can use this bonus action even while incapacitated. 
• Song of Brutality - Aeol makes an attack with his Moonblade, adding his Charisma modifier to the attack and damage roll. 
• Song of Stupidity - One creature within 60 feet must make a Intelligence (DC: 19) saving throw or become blinded and deafened until the end of their next turn
• Song of Fatality - One creature within 60 feet must make a Constitution (DC: 19) saving throw or take 4d8 (20) necrotic damage and have their speed reduced by 20. On a successful save, the creature takes half damage.

Song of Security. If Aeol takes damage, he can reduce the damage by 25.

Aeol can take 3 legendary actions, choosing from the options below.

Cantrip: Casts a cantrip with a casting time of 1 action

Mobile. Aeol moves up to his speed without provoking an opportunity attack.

Unleash Season (2 Actions). Aeol creates an echo in front of a creature he can see within 60 feet, then swapping places with that season. The target is subjected to a rider effect as determined by the season (DC: 19)

• Summer. Become frightened until the end of their next turn. While frightened in this way, attack rolls against them have advantage
• Winter. Become frightened until the end of their next turn. While frightened in this way, they have disadvantage on attack rolls and ability checks
• Autumn. Become charmed until the end of their next turn. While charmed in this way, they spend their action in a hypnotic gaze
• Spring. Become charmed until the end of their next turn. While charmed in this way, their speed is reduced to 0

Aeol can take Mythic actions in place of legendary actions. He can only use this 1 hour after Verdant Apotheosis. 

Blade Dance. Aeol makes a moonblade attack. If it hits, the target takes a penalty to their next saving throw as per Mind sliver

Spellcasting (2 Actions): Aeol casts a spell with a casting time of 1 Action

Delirious Crescendo (3 Actions): All creatures within 20 feet must make a Constitution saving throw (DC: 19) or take 4d8 (20) psychic damage, end concentration on any spells, and become blinded and deafened until the end of their next turn as they hallucinate their most terrible fear. Creatures that were concentrating on a spell take an additional 1d8 of psychic damage equivalent to the level of the spell ended. On a successful save, they take half damage and no other effects.