You may create ephemeral shadows which do your bidding from those you slay while in the shadows.
Prerequisite(s): 6th-level shadowdancer
Benefit: Whenever you slay an opponent while you and the opponent are within a dimly lit (or darker) area, you may create an undead shadow to serve you. This creature is created as if through a create undead spell, except it is a shadow instead of one of the normal undead that may be created with this spell, and the shadow is destroyed automatically after 1 minute per shadowdancer level has elapsed, if it has not already been destroyed. Your caster level for this effect is equal to your shadowdancer level, and you may use this ability once per day per 3 levels of shadowdancer you possess.
Undefeatable: The Collected Feats Sourcebook, Copyright 2009 – 2010, Louis Porter Jr. Design, Inc. Undefeated, Copyright 2011, Louis Porter Jr. Design, Inc.