Todd Spangler NY Digital EditorEpic Games is getting an epic exclusive from K-pop superstars BTS.BTS are coming to battle game “Fortnite” this Friday — with a brand-new music video promising never-before-seen choreography.Epic Games partnered with the BTS on the exclusive music-video premiere, set for Friday, Sept. 25, in “Fortnite” at the Party Royale island’s Main Stage.“Dynamite,” BTS’s first fully English-language song, has become a global hit.