Arayashka

An arayashka is the restless spirit of someone who died of cold and exposure in a frozen land, with a powerful will and a purpose left undone. It looks like a gray, man-sized shadow of mist and appears only in howling blizzards like the one that killed it.

Snow wraiths pick the worst moment, lunging out of the storm to steal heat. Blinding snow, gales and deep drifts hamper them not at all. Once a round they touch for 1d6+1 against the living, and each hit also acts as a chill touch, draining 1 Strength. Lost Strength returns at 1 point per hour; a victim at 2 or less collapses unconscious, and one at 0 dies.

From up to 30 feet they can also pull 1 hit point per round from a single target, a weaker drain they like to use from inside the whiteout without ever revealing themselves. Anyone who loses more than half his hit points to arayashka starts suffering hypothermia. The same drain works on flames and heat sources within 30 feet: one wraith snuffs a normal campfire in 1d3 rounds, and three together can kill a bonfire.

They are immune to sleep, charm and other mind-affecting magic, and to cold, sleet, hail and ice. Fire hurts them badly: ordinary flames, burning oil, hot coals or even a weapon heated in a fire for a round deal 2d4. Otherwise only magical weapons harm them. They are turned as wraiths, and they withdraw if the storm eases.

Each haunts only the place it died and only when the weather is right, so a pass that is safe from spring through autumn turns deadly in winter. Storms seem fiercer wherever they lurk, and the wraith may be calling up the weather itself.

Like most undead they straddle two planes, the Prime and the Negative Material, at once, and that link to negative energy powers their heat drain and immunities. Their craving for warmth is nearly endless. A victim buried near where it fell must be burned on a pyre over which bless is cast, or it rises as an arayashka in the next winter storm. One buried in a warmer land does not return.