Ether Shadow

Ether shadows, also called greater shadows, can mold their bodies into any shape they like, always of the same shadowy substance. They can shift their tone across black and grays to look like solid three-dimensional beings instead of flat patches of dark. If it stays a plain, featureless black, nothing short of continual light gives better than a 10% chance of spotting it.

Their touch is the familiar chill of a shadow but stronger, draining two points of Strength per hit instead of one; the loss wears off in 3-18 turns. Any human or demihuman who hits zero in either Strength or hit points this way rises as a common shadow.

From the Ethereal plane they can show themselves as ghostly apparitions on any neighboring plane, but there they cannot take solid form, so they neither touch nor can be touched. What they can do is slip into a sleeping creature's dreams and steer them, which suggests dreaming may itself be an otherplanar experience. This does no real harm, but they may use it to speak with the dreamer or, more often, to torment the victim with terrible nightmares.

Fighting one means chasing it into the Ethereal or onto its plane of origin. There it is always partly material, open to magical weapons and nearly all spells, though it remains immune to sleep, charm, hold and cold.

An ether shadow is born from a dark ritual that splits a creature's essence in three, so that it lives simultaneously in three places: the Ethereal, the negative energy plane, and the Prime world that hosted the rite.