A Russian friend who is Koryo-saram was born in Tashkent. Her grandparents were deported with the entire Soviet Korean population to the Central Asian republics of Uzbekistan and Kazakhstan from the Russian Far East for fear of collaborating with the Japanese in Manchuria.
The Soviet government's treatment of certain populations or national groups as a whole was devastating from the point of view of the Stalinists, as it was it bound up in the Stalinist conception of socialism itself.
I know you don't think this, but it's unwise to think of the 1930s terror as just 'the purges,' as in the removal of Communist Party members and important people from government institutions, or to see it as just a cynical reorganisation of the bureaucracy by Stalin, as it focuses on the terror only partially. The three state security 'mass operations' affected a huge number of other people.
When the terror was at its height, nearly 700,000 people were put to death within two years (that's from official Soviet documentation, not a figure pulled out of Robert Conquest's arse), and most of them were just ordinary people deemed to be anti-social elements in the new Soviet society in which the foundations for socialism had been laid and a massive and in their minds sincere defence (an inevitability,) of that socialism was mounted.
But that's the deaths. When you came to its attention, the Stalinist government didn't just come for you, it came for your family. A Stolypin carriage awaited them while you met a bullet.