By Tom Balmforth and Parniyan Zemaryalai KYIV (Reuters) – As Russian forces tightened their siege of Mariupol and missiles rained down, Mykhailo Puryshev drove into the city six times last month to evacuate its citizens, somehow surviving despite his red van being all but destroyed. The 36-year-old Ukrainian, who once ran a nightclub in the city, said he evacuated more than 200 people on his six perilous trips and others began to join him in convoy into his hometown. Russia last week claimed control over the ruins of the strategic port city, subject to some of the most intense attacks of the w…