Rashad Evans has little left to accomplish as he drifts into the twilight of his outstanding run as a mixed martial artist. The Niagara Falls, New York, native won Season 2 of “The Ultimate Fighter” reality series, served as a cornerstone for two world-class training camps, captured Ultimate Fighting Championship gold as a light heavyweight and engaged in two of the modern era’s most heated rivalries. Evans, 37, will downshift to 185 pounds for the first time when he meets four-time Olympian Daniel Kelly at UFC 209 on Saturday at the T-Mobile Arena in Las Vegas, where the man they call “Suga” seeks to reinvent himself and avoid his first three-fight losing streak as a professional.