User blog comment:IamJakuhoRaikoben/Chapter 433 & 434: Ikusatsunagi & Demolition Fist, Review./@comment-24546844-20150511182459/@comment-1776824-20150511221233

Igneel was actually much stronger than Acnologia. The only reason lost was because he was not truly alive. The other dragons even said that Igneel only had a fraction of the strength he did when he was fully alive.