User blog comment:Sentomaru/Are Devil Fruits too common?/@comment-972068-20121021233901

Before the Buggy arc: "Axe-Hand Morgan is the most powerful man in all of the world's oceans."

Before the Kuro arc: "Buggy the Clown is the most powerful man in all of the world's oceans."

Before the Krieg arc: "Kuro is the most powerful man in all of the world's oceans."

Before the Arlong arc: "Krieg is the most powerful man in all of the world's oceans."

Alternatively,

Before the Grand Line: "It's a horrible sea; the pirate graveyard. Do not go unless you want death."

Before the New World: "It's a horrible sea; the pirate graveyard. Do not go unless you want death."

In One Piece, everything is greatly exaggerated before they actually appear. Devil Fruits are no exceptions.