Source?
Wait .. you think I'm surprised about the Obama administration and the Clinton State Dept. essentially training and funding militant groups with 2nd and 3rd degrees of separation from IS?
Nope. Not surprised at all. But no, I didn't see that video.
But that said -- you know what would happen if IS killed off all the non-believers? They'd start killing each other over the Sunni vs Shia divide. That should tell you all you need to know about that ideology.