Croatian MMA/ BJJ Fighter Goran Reljic trains under the Redzovic brothers (Eddie and Adem) in their academy in Chicago. Reljic has been training BJJ for a long time and has spent time training directly with Roger Gracie in London. 2 years ago he was promoted to BJJ black belt by the Redzovic brothers. Goran is the current KSW light heavyweight champ.
Check out this guillotine grip he uses: