Shadow control

You have somehow transferred your soul into your body and now have your shadow under control.

-Your shadow can attack other's shadows within 5ft of you using the same weapon you are holding.
This increases by 5ft at 15th and 20th level.
If your shadow attacks your opponent's shadow, inflict the damage done to the owner's shadow. Your opponent's shadow cannot attack back unless they too have the 'Shadow Master' feat.

-Starting at the 5th level, you have the ability to control your opponent's shadow as well, if your combat is in a place where you can see your opponent's shadow and it is within 30ft of you, for example against a building in the middle of the day. Controlling your opponents' shadow decreased their walking speed by 10ft, and for every 5 levels, the decreased walking speed increases by 5ft, and the reach increases by 15ft.
In addition, your opponent's shadow can attack the owner of the shadow with one of his or her weapons. Doing so acts as the controlled shadow being part of the battle, so the shadow has its own initiative.
You can only control one shadow at a time.

The extra attack does work if you are using your shadow, but any kind of multi-attack is lost if using an opponent's shadow.