I trimmed this video so it cuts out the beginning part where everyone kills the Acolyte and the Knights. I like this video because it covers the worst case scenario (kind of). Three things that went wrong: 1) We had no titan, so no bubble was used to distract boomers. 2) When I attacked Crota, boomers hit me, but did not kill me. 3) On the second 'round' the sword bearer went behind the left wall. Whoever runs sword, it is their responsibility to get the sword bearer back in the middle and agro him. Hope this video helps. I run this routine every time I do Crota, whether normal or hard mode.