Assault! The Mysterious Blader (襲撃！謎のブレーダー, Shūgeki! Nazo no Burēdā) is the fifteenth episode of the Beyblade: Shogun Steel season and the 169th episode of Metal Saga. It aired on July 15, 2012 in Japan.
At the WBBA, Zyro and Co are assigned to demonstrate Zero-G battling around the nation. The gang seperate to different locations but once the battles get underway a mysterious blader disrupts the demonstration battles. As Kite and Eight start thier match a beyblader shoots a beyblade from the shadows disrupting the match disappearing as quickly as he appeared. At a different stadium, Ren and Takanosuke get a demonstration battle underway then the mysterious blader, Sakyo Kurayami, stops the battle and knocks out both of their beys like he did to Kite and Eight with his left rotation bey, Dark Knight Dragooon.
Zero-G Stadiums are fitted all around the world, with Zyro and the gang being the representatives for stadiums in Japan, along with the Synchrom System.
A new Blader, Sakyo Kurayami, travels around all the stadiums, sabotaging the representatives' battles.