The Artificial Fruits were developed by Vegapunk and Donquixote Doflamingo.

What is most powerful Devil Fruit?

Bari Bari no Mi allows the user to produce unbreakable barriers, giving them protection from most enemies in their way in the process. Even someone as strong as Kozuki Oden couldn't break the barrier produced by this fruit, making it the most powerful Devil Fruit when it comes to defense.

Who has awakened their Devil Fruits?

In One Piece, a select few characters manage to awaken their Devil Fruit.
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One Piece: Every Awakened Devil Fruit, Ranked