Several actors have previously taken on the role—Mickey O’Rourke in 2008 and Orlando Bloom more recently in “The Cut”—and now Dwayne Johnson has stepped up to portray UFC trailblazer Mark Kerr. The story unfolds during a period when he's able to support himself and his girlfriend, Dawn (Emily Blunt), though their lifestyle is far from extravagant. To achieve financial security, he needs to win the Grand Prix in Japan…