Tenrou never fell. Acnolgia left it for the promise of a great battle and so for 4 years, Natsu set off from his home to train. However, only a year in he learns to use God Slaying Fire before going on to obtain the ability to use Devil Slaying Magic. With it, he will undo a curse that has plagued the land for years. He is the All Slayer... and he will kill a God. NatsuxHarem