Last night <Promethean> of US-Malfurion killed Paragons of the Klaxxi World 19th & 5th US 25 Man.
However, it seems they were cheating but I want more opinions. The exploit is, if you tank Iyyokuk behind a corner and Line Of Sight your raid, he won't cast Fiery Edge on raid members LoS'd. They might have also Line of Sigh'ed Xaril to remove Catalyst from the encounter.
Here is a picture of their World of Logs clearly showing Firery Edge hitting small amount of people i.imgur.com/GHlvn53.png