User blog comment:FairyRaven/Fairy Tail Chapter 427: Pitched Underground Battle, Review and Commentary/@comment-24277053-20150406115422/@comment-1359322-20150406121449

There are total 8, Natsu beat 3. So there's 5 left, minus Gray would be 4. But i wouldn't put it beyond Gajeel to defeat remaining 4 himself, considering that he's as strong as Natsu, and he does have the Rune Knights and Lily with him.