I see, then what about this: Would Makarov be able to hold Acnologia back like he did on Tenrou? We know that Acnologia went easy on them, but still, the master was wounded too. If the is able to hold it back, they just need to cut off it's head. No matter how strong it is, it will die when it's head is cut off. And there is no magic needed to do such thing. But again, it would break the story, lol.