New Musclemania® World Champions Nathan Wallace, Open (L) and Kwame Jack-Duah, Junior (R) were a big surprise to the Las Vegas audience last weekend in Las Vegas. Nathan is an avid powerlifter in the off-season and added 10 lbs. of muscle since his last MM World in 2011. At 5'9", 196 lbs., Kwane is a 19 year old phenom who won MM Australia a few weeks before.