In the latest chapter, Magnolia's Line of Defence, Erza was getting beaten by Ajeel Lamur. This kind of reminds me of Natsu's fight with Aria in the Phantom Lord arc. I think I have a good idea of what the outcome's gonna be. Natsu and Happy are going to go back to help Erza while Gajeel, Wendy, Panther Lily and Carla stay behind and fight the Ajeel Squad. Erza's still trapped in Ajeel's Sand Trap and when he starts suffocating her to death, Natsu lands a Fire Dragon's Iron Fist in Ajeel's jaw and both of them go off the ship and onto the ground. From there, the two start fighting. The last thing Erza said to Natsu in the Phantom Lord arc was that he's the one to surpass her. Is this the day that happens? Also, Natsu and Ajeel countered each other twice already. I think it's obvious the Salamander and the Desert King were gonna duke it out man-to-man sometime. If Natsu is strong enough to kill Ikusa-Tsunagi, Zeref and Acnologia, then Ajeel shouldn't be any trouble. Especially if Natsu can enter Dragon Force at will.