User blog comment:FairyRaven/Fairy Tail Chapter 401: Igneel vs. Acnologia, Review and Commentary/@comment-7418318-20140923095340/@comment-1359322-20140923142834

Or Fire Dragon's Steel Fist is Igneel's version of the punch.

@Nick, That would be cool. Wait since the title of this part is Unlimited Pain could it be that END possessed Igneel and Natsu has no choice but to kill him. O_O