User blog comment:Omega natsu2/Chapter 372: Breach, Predictions./@comment-24536822-20140215073714/@comment-7418318-20140215090432

As B214 said, he ate the explosions and on top of that he has ridiculous magic power reserves and durability. Romeo has neither of thsoe two and can't eat explosions. Not to mention he has far less battle experience than Natsu.

Also remember that even with all his enhanced abilities and stuff Natsu was still knocked out cold by Jackal and could only re-engage after being healed by Wendy.