User blog comment:IamJakuhoRaikoben/Chapter 493: The White Dragneel, Review./@comment-5288632-20160713060020/@comment-7418318-20160713073751

That's one of the big questions.

Though when he fired off his first death-wave his parents and little brother were already dead... they (primarily Natsu) were his reason for the research that got him cursed after all, so there was no living relative to kill for him in the vicinity.

Now the firs question for me is WHAT is Larcade. Is he a demon or some other sort of artificial being that Zeref created? Once we know that, the other questions will probably fall into place by themselves.