is one piece episode 658 filler?

More of the losing contestants of Block C of the tournament are dumped into the pit, and the group of fighters ponder how to escape. Ricky is amazed that such a place exists underneath the kingdom.

Tank notices something about Ricky and steps forth, before hesitantly asking if he's the former king of Dressrosa. Ricky, having no reason to hide his identity any longer, removes his helmet and confirms that he is indeed the former king, Riku Doldo III.