Boon of Immortality. Endelyn is immune to any effect that would age her, and she can't die from old age.
Eclipsed Doom. Endelyn can be killed only if she is reduced to 0 hit points during a solar eclipse or while she is within 60 feet of a symbolic representation of one. Otherwise, Endelyn disappears in a cloud of inky smoke when she drops to 0 hit points, along with anything she was wearing or carrying, and reappears 24 hours later in the same location or the nearest unoccupied space.
Uncanny Awareness. Endelyn can't be surprised.
Spellcasting. Endelyn casts one of the following spells, requiring no material components and using Charisma as the spellcasting ability (spell save DC 14):
At will: detect magic, mage hand
1/day: plane shift (self only)
Multiattack. Endelyn makes two Puppeteer's Lash attacks
Puppeteer's Lash. Melee or Ranged Spell Attack: +6 to hit, reach 5 ft. or range 60 ft., one creature. Hit:17 (4d6 + 3) psychic damage, and if the target is Large or smaller, Endelyn telekinetically moves it up to 10 feet in any direction horizontally.
Endelyn, also known by the names Creeping Lyn and Bitter End, is the youngest member of the Hourglass Coven. People come to her to learn about their futures, which she spells out through grotesque theatrical pageants. As payment, she snatches away a portion of each client's free will, preventing them from taking certain courses of action in their lives. Her petitioners often learn of a dreadful fate that awaits them but find themselves unable to prevent it due to the cursed terms of their deal.