be the making of somebody/something
be the making of (one)
To be a positively transformative event in one's life. He used to be irresponsible with money, but buying a home was the making of him—he's never been late with a single payment! In many ways, surviving that internship was the making of me.
be the making of
Be the means or cause of progress or success, as in Marriage will be the making of him. This idiom, using making in the sense of "advancement," was first recorded about 1470.