仮面ライダー剣
was chosen by the B.O.A.R.D. organization to use the sealed "Category Ace of Spades" (Change Beetle) to become Kamen Rider Blade. He has a good heart and believes in fighting to protect humanity. He would ultimately sacrifice his own human existence by mutating into the second Joker after excessive use of his Rider form's King Form transformation. This forces a stalemate in the Battle Fight while there is more than one Undead, keeping mankind safe while allowing his friend Hajime, the original Joker, to continue living among humans. Kazuma makes return appearances in "Kamen Rider Decade" and "Kamen Rider Zi-O"; the latter of which saw his humanity restored.