Is Natsu in Dragon force mode the strongest Fairytale character (Besides Mavis and Zeref) i mean by the looks of it he seemed really really powerfull... Also Does Natsu ever go Dragonforce again after his fight with Zero
Hmmm he is definitely one of the most powerful members in FT but in the world, who knows. I would like to think he can match it against the 10 wizard saints or whatever they are called but tbh we have only seen one of them and that is Jura, aside from Makarov of course.
After that point...if your happy with spoilers then...
He doesn't use Dragonforce anymore after this fight, it seems that he cannot unlock at will