Maybe Zhenya told him those riddles and let him live on purpose. I don’t know, it’s just that I’ve been re-reading this, and it doesn’t make sense that he let him go alive after telling him the 'weakness' of his family aka the riddles—knowing damn well that he’s good at analyzing and memorizing things. So maybe… just maybe, he did that horrible thing on purpose because he knew he wouldn’t stop after having his pride hurt like that so maybe Zhenya expect that he’d come back to complete his mission.
Maybe Zhenya told him those riddles and let him live on purpose. I don’t know, it’s just that I’ve been re-reading this, and it doesn’t make sense that he let him go alive after telling him the 'weakness' of his family aka the riddles—knowing damn well that he’s good at analyzing and memorizing things. So maybe… just maybe, he did that horrible thing on purpose because he knew he wouldn’t stop after having his pride hurt like that so maybe Zhenya expect that he’d come back to complete his mission.