User blog comment:LastationLover5000/Chapter 411 - In Which What The Hell Did I Read (Quid Pro Quo)/@comment-21119641-20141201190208

The only odd thing for me in the chapter was...Gray falling down only to get up and Natsu activating Dragon Force out of nowhere...I liked Gray's Demon thing, it sounds interesting, I just don't want him to succumb to this...seriously Gray wouldn't turn good as an antagonist. And to be honest, I thought Mard was stronger, seriously, without power-ups only Gray could freeze/damage him, after his Etherious Form had been activated, I seriously thought Jellal would pop in and try to fight him.

And yeah it seems that spell Natsu used is the same he used to defeat Zero, although I was expecting him and Gray to attack at the same time...