Pavel Mif by all Chinese accounts was a ruthless scheming Napoleon (the one in animal farm). Fortunate to the Chinese, Mif was later purged by Stalin. I wonder what sort of family he was from; where he was raised, etc.
As with many Soviet activists who did not get to publish their memoirs, early life of Pavel Mif (real name - Mikhail Alexandrovich Fortus) is a mystery. The only thing that is known for sure - he was born in 1901 in Bolshaya Alekseevka village of the Kherson Governorate of Russian Empire. His surname indicates that he might be a Jew, but that's not certain.
Data on his biography is better available from his adulthood, starting with 1920, when he enrolled in Sverdlov Communist institute. For example, there's this article from 1972 in Russian, that deals with his work as a sinologist and a Comintern member. It points to Mif's critique of Mao and his faction as a reason for a negative opinion on Mif in China, but it might be biased against China in general, as it was written at the height of Sino-Soviet split.