The Undefended is an awesome guillotine set up off of the Rubix Cube. In the video Jeff Barney demonstrates and walks us through the technique.
The name of the technique fits it perfectly because once you are in position to lock in the guillotine your opponent is completely defensless.
From the Rubix Cube you sweep your opponent over onto their back and pin the arm to the mat that was trapped by your shin. Your opponent's other arm will be blocked by your body so they do not have either hand free in order to defend the choke.
Don't let Marcelo Garcia get ahold of this one. He is already choking people out from the mount when they have two hands to defend with !