You cited, as an encyclopedic fact, 10M as having perished specifically "Yagoda's torture chambers" per your words, which can only refer to NKVD (or otherwise "political") persecutions -- not the various deportations en masse or the Holodomor. The WP page you cited confirms upper bound for the former set of excess fatalaties (i.e. the one that you were explicitly referencing) at 770k -- which we shall charitably round up to 1M for the sake of "civility" here -- for the entire USSR during the pre-war era.
Far short of the 10M figure you are introducing for whatever imaginitive and creative purposes.
Again: 10M in this category -- the number who perished "Yagoda's torture chambers" throughout the USSR before the start of the war; and "about half" being in Ukraine; or around 5M, is the number you put forth -- apparently for the nifty rhetorical effect you thought it might bring.
Whereas the historical consensus for this category is <400k.