User blog comment:B214/Chapter 433 & 434 in a nutshell/@comment-5303512-20150511130513/@comment-1359322-20150511134545

Seriously i don't see any similarities in those two though. In the one against Jackal, it became BS the moment Natsu ate the explosion by Jackal, something i don't think is possible even now. While in this one, Natsu didn't really pull off much of a BS like that one, he just used 1 attack he named based on his adoptive father which if you consider how Dragon Slayers can change their bodies into that of a Dragon, then why can't Natsu changed his from a Fire Dragon to a Fire Dragon King.