Why did Safin let Mathilde go?

Why did Safin let Mathilde go? Safin let Madeleine live so that he could ensure that, not only would she know the pain of losing her parents as he had, but she would know the pain of losing her love, too.

Safin let Madeleine live so that he could ensure that, not only would she know the pain of losing her parents as he had, but she would know the pain of losing her love, too.