User blog comment:FairyRaven/Fairy Tail Chapter 401: Igneel vs. Acnologia, Review and Commentary/@comment-7418318-20140923095340/@comment-7418318-20140923143609

Interesting twist you suggest there.

So first Igneel is fighting against Acnologia, but it's made very clear that he can't win. Somehow Natsu manages to get the book and while he sees his father being beaten back more and more the book keeps whispering to him, trying to convince him that it can save Igneel.

And just when Acnologia is about to land the killing stroke, Natsu gives in an opens the book, resulting in Igneel's possession. Then "ENDneel" overpowers Acnologia, showing off just how terrible this Demon in a Dragon really is, setting up the final fight of the arc with everyone (or at least every Human) ganging up on ENDneel.

That'd be quite the intense and dramatic situation and would fit the part's title too.