Shadowcutter

SCP-XXXX

Item #: SCP-XXXX

Object Class: Safe

Special Containment Procedures: SCP-XXXX is to be contained within a small locked steel container. any access to SCP-XXXX is strictly for experimental purpose and is to be granted by the O5-Council.
SCP XXXX-1 is to be immediately killed within 24 hours after spawned. if immediate termination was not possible, SCP XXXX-1 needs to be contained in a small 3x3 fully lit concrete room with a surveillance camera and immediately terminated after 24 hours has passed

Description: SCP-XXXX is a standard blade cutter that can be used normally to cut any inanimate objects and/or household items. the anomalous property only appear when the blade of SCP-XXXX came into contact with a surface of human shadow, if used on a shadow the blade will appear to cut through the shadow separating the shadow from the human subject leaving the subject shadowless. this only works if the subject cut his/her own shadow. using SCP-XXXX to cut another person shadow does not do anything, therefore testing SCP-XXXX on animal held no result because no animal would 'willingly' cut its own shadow.

the separated shadow will then manifest itself on a 3 dimensional plane and move autonomously seemingly with its own consciousness, this instance is called SCP-XXXX-1. despite being featureless, SCP-XXXX-1 still retain the physical outline of its original subject, copying any physical trait/deformities the subject might have.
SCP-XXXX-1 could not be harmed with any conventional method, therefore can not be terminated. the only way to terminate SCP-XXXX-1 is to kill it using SCP-XXXX as a weapon or killing the subject owning the shadow.

if SCP-XXXX-1 was not immediately terminated within 24 hours of it spawning, it will regain all of the subject features, transforming itself to a human with identical physical appearance to that of its subject. while the subject him/herself will turn into SCP-XXXX-1 shadow in a sort of 'role reversal'

while SCP-XXXX-1 seem docile at the first 5 hours of it spawning, obeying any order its 'creator' gives, it will slowly gain sentience and self awareness overtime, manifesting the subject evil personality and the subject physical feature. at this point SCP-XXXX-1 will start disobeying order and act aggressively towards the subject, treating the subject as if he was the shadow and it was the real human. SCP-XXXX-1 will actively stalk in order to kill the subject and speeds up the 'role reversal' progress. if SCP-XXXX-1 managed to kill its creator, the subject will then disintegrates and turn into SCP-XXXX-1 shadow. in any case, if the role reversal succeeded and SCP-XXXX-1 turned into full 'human' it will be vulnerable to physical contact and can be terminated with conventional method. but the original subject will be killed along with it.
terminating the subject before the role reversal is complete could also terminate SCP-XXXX-1.