Dragon King

Shogi
The ryuou or dragon king is the most powerful piece in regular shogi, and pretty close to this title in larger shogi variants most of the time.It can move one square in any direction and has the move of a rook, making it capable of taking out several pieces by itself before it gets captured.

Chu shogi
This piece is now a starting piece. Amazingly, it becomes even more powerful as a Soaring Falcon when promoted. (How is a falcon more powerful than a king?)