By John Morgan, The Underground ‘Thug Nasty’ believes his purpose extends beyond MMA. ‘Shut up and fight’ is not an option. LAS VEGAS – As Bryce Mitchell nears the biggest fight of his career, facing a proven contender in a featured bout of a major UFC pay-per-view event, the spotlight focused on “Thug Nasty” continues to intensify. The undefeated featherweight has used much of the new attention not just to further his career but also to discuss his political beliefs, a practice that has begun to bring him his share of criticism along with some added support. But Mitchell said despite some pus…