Stalin himself is credibly alleged to have had sex with a minor girl, and IIRC gotten her pregnant.

As unfortunate as the behavior of Beria was, powerful men using their power to rape women is something that goes way back. So it's not exactly extraordinary.

Castrating and mutilating kids is of another order. But that's one example. It's often pointed out that these people are great examples of the Lumpenproletariat.