KYIV, July 14 (Reuters) - He wears a pistol to interviews with foreign journalists and discusses wartime intelligence. In parts of his interview reported by Reuters earlier this week, he said the mutinying Russian mercenaries had headed for a nuclear base in pursuit of a backpack-sized atomic weapon. In late May a Russian air strike hit his headquarters on Kyiv's Rybalskyi Peninsula, sparking Russian media reports that he had been gravely wounded