User blog comment:FallenShadow/Fallen's Reviews: Chapter 341-343/@comment-7418318-20130711173547/@comment-7418318-20130712120608

I guess that depends on what the eternal flame really is.

If the source of the flame is the real eternal thing, Natsu could eat the flame without becoming like Atlas Flame and without destroying it in the process, which is more important.

Come to think of it, I wonder if Dragon Flames are able to melt iced shell.