Archfey

Fortitude. If damage reduces the Archfey to 0 hit points, it can make a Constitution saving throw with a DC equal to 5 + the damage taken, unless the damage is necrotic or from a critical hit. On a successful save, the archfey drops to 1 hit point instead.

Legendary Resistance (1/Day). If the archfey fails a saving throw, it can choose to succeed instead.

Magical Resistance. The archfey has advantage on saving throws.

Multiattack (3/Day). The Archfey makes three attacks with Arcane Burst.

Arcane Burst. Melee or Ranged Attack Roll: +11, reach 5ft. or range 60 ft., one target. Hit: 26 (4d12) necrotic damage.

Spellcasting. The Archfey casts one of the following spells using Intelligence as the spellcasting ability (save DC 19):

at will: invisibility, detect thoughts, alter self, disguise self, message, prestidigitation

3/day each: geas

1/day each: bestow curse (9th-level version), teleport, Mordenkainen’s magnificent mansion, tasha’s bubbling cauldron, create undead (Deathlock wight), legend lore, scrying, find familiar (sprite), ceremony (dedication only), magic weapon, air bubble, warp sense, mordenkainen’s private sanctum, fly, dispel magic, sending, plant growth, project image, negative energy flood, aura of life (no concentration required), dominate monster (undead only)

Wish (2/Day). The Archfey casts the Wish spell, using Intelligence as the spellcasting ability (spell save DC 19). The Archfey doesn’t suffer any of the penalties that normally follow casting the Wish spell to produce an effect other than duplicating another spell. After casting this spell, the archfey takes 40 (9d8) Necrotic damage, which can’t break its concentration on a spell, and gains 1d4 levels of Exhaustion.

Fey Step. The archfey teleports, along with any equipment it is wearing or carrying, to an unoccupied space it can see within 30 feet of it.

Rebuke (3/Day). When the archfey is damaged by a creature within 60 feet of the archfey that it can see, the creature that damaged the archfey must make a DC 19 Dexterity saving throw, taking 31 (7d8) fire damage on a failed save, or half as much damage on a successful one.