There was a golden era during which magic was advanced and widespread. Legends say it was due to the Empire known as The Phoenix. Now thousands of years later, this is a tale often told to children and while there is evidence that it existed, its glory has been forever lost.

A boy from earth reincarnates in this world.

This does seem like an overused concept. It probably is... There should be some changes from around chapter 10 though..but I still don't know if that hasn't been done already or not.