I'm pretty sure this makes Mirror fairly useless.
That depends on whether or not adding reflect makes the shield untargettable.
If not, then the shield becomes prime target for deflags.
Also, if this is placed on boneshield, does it affect all bones in the stack or just the top one... because if it only affects the top, watching the opponent's stunned disbelief would be pretty hilarious.
On a different note, this mechanic has been proposed before MANY times. You may want to go do a few searches. You may need to do some more work to set it apart.