Deimavigga

A creature with greater darkvision can see perfectly well in areas of darkness and dim light, though such vision is in black and white only. A creature with greater darkvision can see through even forms of magical darkness.

A monster with telepathy can communicate mentally with any creatures within the listed radius, as long as they share a language. This doesn't give any special access to their thoughts, and communicates no more information than normal speech would.

Any creature capable of comprehending speech understands the deimavigga, as if they constantly spoke in all languages at once.

Trigger A creature within 60 feet is targeted by a spell that would restore Hit Points or provide a status bonus (the deimavigga automatically recognizes such effects) Effect The deimavigga whispers disturbing lies, audible only to the target, to shake the target's faith in the spell's caster. The target must attempt a DC 38 will save. Critical Success The target disbelieves the lies and receives the intended benefit of the spell; the target becomes temporarily immune to Whispers of Discord for 24 hours. Success As critical success, but the target isn't temporarily immune. Failure The spell fails to affect the target. The target refuses all aid from that caster for 1 round and doesn't count as the caster's ally. Critical Failure As failure, but the duration is 1 minute.

A deimavigga's razor-sharp claws can slice through reality, allowing them to make claw Strikes and use spells with a range of touch against any creature they can see directly or via magic. A creature targeted in this way can retaliate until the start of the deimavigga's next turn; it can target the devil's claws as if the devil were physically present and adjacent to the target, though the claws are Concealed.

The deimavigga can take on the appearance of any humanoid. This doesn't change their Speed or attack and damage bonuses with Strikes but might change the damage type their Strikes deal (typically to bludgeoning). The monster changes its shape indefinitely. It can use this action again to return to its natural shape or adopt a new shape. Unless otherwise noted, a monster cannot use Change Shape to appear as a specific individual. Using Change Shape counts as creating a disguise for the Impersonate use of Deception. The monster's transformation automatically defeats Perception DCs to determine whether the creature is a member of the ancestry or creature type into which it transformed, and it gains a +4 status bonus to its Deception DC to prevent others from seeing through its disguise. Change Shape abilities specify what shapes the monster can adopt. The monster doesn't gain any special abilities of the new shape, only its physical form. For example, in each shape, it replaces its normal Speeds and Strikes, and might potentially change its senses or size. Any changes are listed in its stat block.

The deimavigga whispers a terrifying multiversal truth to one adjacent creature, shaking its faith in reality and divinity. The target must attempt a DC 38 will save. Celestials and fiends gain a +2 status bonus to this save. Critical Success The target is unaffected and temporarily immune to Whisper Earworm for 24 hours. Success The target is unaffected. Failure The next time the target rests, it ruminates on the deimavigga's words instead of sleeping or otherwise resting and awakens Fatigued. The target also becomes Drained 1 and Stupefied 1 until it's no longer fatigued. Critical Failure As failure, but Drained 2. After this rest, the target must attempt another DC 38 will save. On a failure, the target becomes Stupefied 2 and takes a –4 status penalty to Will saves against effects from unholy creatures. These effects last until the target unlearns the truth spoken by the deimavigga, requiring a Rewrite Memory spell, other means of modifying their memory, or powerful magic such as a Wish ritual. Effect: Whisper Earworm (Critical Failure)