User blog comment:IamJakuhoRaikoben/Chapter 462: Battlefield, Review./@comment-75.175.65.190-20151117060359

Natsu going to Zeref if anything is a advantage for Zeref as Natsu is pretty much by himself (with only Happy with him) so Zeref could easily use this opportunity to awaken Natsu as END then either he can stay with Zeref until they reach Magnola or just sent him to attack his guild and either way would be a shock to his comrades in the long run.