Soulsliver

A soulsliver is an extradimensional shapechanger that lurks in the half-dimensions behind mirrors. It watches creatures on the Material Plane through reflective surfaces, assumes their likeness, then crawls through the mirror to kill and feast upon its prey. Whether they are bizarre offshoots of the doppelganger race or originate from some aberrant magic used to create a demiplane, soulslivers are responsible for many unsolved murders, and their mirror travel makes them hard to catch.

A soulsliver causes trouble for a short while in its assumed form, then retreats through the mirror to its home plane. Its native plane is an aspect of the Plane of Shadow, with reversed and grossly distorted creatures and scenery from the Material Plane.

Death Throes — When a soulsliver is killed, its body explodes into jagged glass shards that deal 2d6 points of piercing and slashing damage to creatures within a 20-foot-radius burst (Reflex DC 12 half). The save DC is Constitution-based.

change shape (any humanoid, alter self)

compression

Mirror Travel — At will as a standard action, a soulsliver can crawl into any mirror as if it were a door or window, instantly transporting itself to another mirror within 500 feet as if using dimension door (caster level 7th). It can remain within that mirror indefinitely, or on its next turn crawl out or use this ability again. Its compression ability allows it to enter or exit Diminutive or larger mirrors. It can only exit a mirror if it is using change shape to take a specific creature's form.

Perfect Copy — When a soulsliver uses change shape, it can assume the appearance of a specific individual. However, it is always the mirror image of the person it copies, which might give away that something is wrong.

sound mimicry (voices)

Dodge, Improved Initiative

Acrobatics +9 (+13 when jumping), Bluff +7, Disguise +7 (+11 when using change shape), Perception +7, Sense Motive +7, Stealth +9