Aero, King of Roses

Magic Resistance. Aero has advantage on saving throws against spells and other magical effects, and magic can't put him to sleep.

Magic Weapons. Aero's weapon attacks are magical.

Legendary Resistance 3/Day. When Aero fails a roll he can choose to succeed instead.

Spellcasting. Aero is an 10th-level spellcaster. His spellcasting ability is Charisma (spell save DC 24, +13 to hit with spell attacks). Aero has the following bard spells prepared:

Cantrips (at will): control flames, infestation, prestidigitation, vicious mockery

1st level (4 slots): absorb elements, inflict wounds, shield, silvery barbs

2nd level (3 slots): healing spirit, shatter, web

3rd level (3 slots): counterspell, plant growth, spirit shroud

4th level (3 slots): blight, confusion, greater invisibility

5th level (2 slots): cloudkill, contagion

Multiattack. He makes three attacks with his rapier.

Poison Rapier. Melee Weapon Attack: +17 to hit, reach 5 ft., one target. Hit: 20 (3d8+7) piercing and 14 (4d6) poison damage. On a hit, the target must succeed on a DC 24 Constitution saving throw or become Poisoned for 1 minute. The target may reroll the save at the end of their turn.

Beguiling Presence. Each creature of Aero's choice that is within 120 feet of the king of nightmares and aware of him must succeed on a DC 24 Charisma saving throw or become charmed for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to Aero's Beguiling Presence for the next 24 hours.

Back Stab 5/Day. As a bonus action the Aero can imbue a strike with 90 (20d8) poison damage.

Aero can take 3 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. Aero regains spent legendary actions at the start of his turn.

Hide (Costs 1 Action). Aero takes a legendary action to hide.

Attack (Costs 1 Action).  Aero makes a rapier attack.

Cast a Spell (Costs 2 Actions). Aero casts a spell.