So what if, in an attempt to unite the crumbling remnants of the Khazar Empire, Sviatoslav adopted Judaism? I know he normally wouldn't of done that (seeing Judaism as inferior because he and his pagan martial might defeated the Khazars), but could there be any circumstance in which Sviatoslav could either have converted to Judaism himself, or had his son(s) brought up in the Jewish religion?
Could, for example, Sviatoslav getting captured in his younger years and made a well-treated Khazar slave before he comes back to the Rus change his perception of Judaism?