User blog comment:IamJakuhoRaikoben/Chapter 479: Who you should show the greatest respect to is, review./@comment-24800928-20160330160837/@comment-7418318-20160330202735

Didn't Zeref say that he considered the people of Alvarez as his pieces in a game and that's how he can avoid firing death-waves left and right?

Maybe he chose his "pieces" for the amusement value rather than their battle value.