Yep, that's the stuff. You need a lot of things to make it work, but there are a lot of things that make it work. Quicksilver, Reflex, Badge of Courage, Tikki Tooki, CYDSTEP, GETINDERE, WEYTWUT, Earthmother, Namtar's Ward and probably a few other things I'm forgetting. No single item on the list is required, but you do have to get several simultaneously.
EDIT: When this was first discovered, we had the pre-nerf trisword. This made the bosskill so trivial that Lujo refused to use it in his thread.