User blog comment:HelloFalman/Ankhseram Magic Inablity/@comment-5894890-20150807024228

Well, Zeref been saying Natsu is the one to kill him since the Tenrou arc. Not to mention Natsu is the main male protagonist, thus defeating the main antagonist sounds about right. And if you haven't read the manga, I won't spoil it for you... but there's a huge reason there. Also, wasn't the more he holds something dear to him, the more likely something dies (curse takes affect/ power unleashes). Which is why is tries to hold back the emotion for anything he cares about o_o.