Here's a video that never gets old:
The degenerate fun on display is essentially this:
Man plays Dream Halls…
If you see your opponent put this on the table, you KNOW he or she is up to no good. Just like the Marauder's Map, Dream Halls lets you get into all sorts of mischief. In this case, getting big bad guys into the play super fast. I covered most of them in Rise…of the Monsters!
For backup, he happens to have Door to Nothingness.
The beauty of Door to Nothingness is in it's simplicity. If you have a near-infinite source of mana, as this gentleman did, you can simply counter a spell or effect you don't like by annihilating the player casting it. The spell then drops off the stack before it resolves.
What happens next? The victim…who goaded him into using it…unmorphs his Willbender.
Most things of this kind affect "spells," Willbender is one of the few that also affect "abilities". So the guy with all the stuff uses the door, and in response the targeted player redirects it back to the original rabble-rouser. This video is what made me add Willbender into my own deck. It's about 25¢ in any bulk bin. And it saves your butt when you least expect it.