Arch-hag

If the hag fails a saving throw, it can choose to succeed instead.

The hag has Advantage on saving throws against spells and other magical effects.

When the hag drops to 0 Hit Points, it dies only if it is within 30 feet of its anathema (a thing the DM chooses as the hag's most hated thing). Otherwise, the hag drops to 1 Hit Points and teleports to a harmless demiplane, and it can't return to the plane it left for 2d6 days. When the hag teleports away, each creature within 60 feet of the space it left is cursed. Until the curse ends, a creature has Disadvantage on ability checks and saving throws, and the hag knows its location anywhere in the multiverse.

The hag makes two Spectral Claw attacks and uses Crackling Wave.

Melee or Ranged Attack +14, reach 10 ft. or range 60 ft. 17 (3d6 + 7) Force damage. If the target is a Large or smaller creature, it has the Prone condition.

DEX Save DC 22, each creature in a 60-foot Cone [Area Of Effect].
Failure: 32 (5d12) Lightning damage.
Success: Half damage.
Success or Failure: The target is cursed until the end of the hag's next turn. The target can't take Reactions until the curse ends.

Each creature cursed by the hag and within 60 feet of it takes 14 (4d6) Lightning damage.

The hag makes one Spectral Claw attack.

The hag uses Spellcasting to cast Dimension Door or Hypnotic Pattern. The hag can't take this action again until the start of its next turn.