Aubade of the Unseen Wilds

Amphibious. She can breathe air and water.

Innate Spellcasting. Her innate spellcasting ability is Charisma (spell save DC 12). She can innately cast the following spells, requiring no material components:

At will: dancing lights, minor illusion, vicious mockery

Mimicry. She can mimic animal sounds and humanoid voices. A creature that hears the sounds can tell they are imitations with a successful DC 17 Wisdom (Insight) check.

Shared Spellcasting. While all three members of the Tripartite Primus are within 30 feet of one another, they can each cast the following spells from the wizard’s spell list but must share the spell slots among themselves:

1st level (4 slots): identify, ray of sickness

2nd level (3 slots): hold person, locate object

3rd level (3 slots): bestow curse, counterspell, lightning bolt

4th level (3 slots): phantasmal killer, polymorph

5th level (2 slots): contact other plane, scrying

6th level (1 slot): eyebite

For casting these spells, each sister is a 12th-level spellcaster that uses Intelligence as her spellcasting ability. The spell save DC is 13, and the spell attack bonus is +5.

Claws. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) slashing damage.

Illusory Appearance. She covers herself and anything she is wearing or carrying with a magical illusion that makes her look like another creature of her general size and humanoid shape. The illusion ends if the she takes a bonus action to end it or if she dies.

The changes wrought by this effect fail to hold up to physical inspection. For example, she could appear to have wrinkly skin, but someone touching her would feel her smooth skin. Otherwise, a creature must take an action to visually inspect the illusion and succeed on a DC 20 Intelligence (Investigation) check to discern that she is disguised.

Invisible Passage. The sister magically turns invisible until she attacks or casts a spell, or until her concentration ends (as if concentrating on a spell). While invisible, she leaves no physical evidence of her passage, so she can be tracked only by magic. Any equipment she wears or carries is invisible with her.

Aubade of the Unseen Wilds: As part of the Tripartite Primus, when her HP is reduced to zero, Aubade's corporeal form dissolves into mist and all creatures within 120 feet must make a DC 20 wisdom saving throw. If successful the creature is rendered unconscious for 8 hours. If the creature fails the saving throw, and they have harmed an animal within the past 24 hours their HP is reduced to 0.