Shiro Kanzaki

Shiro Kanzaki (神崎 士郎 Kanzaki Shirō) is the mysterious antagonist of Kamen Rider Ryuki. Shiro is the creator of both the Mirror Monsters and the Card Decks used by the Riders participating in the Rider Battle, and Yui Kanzaki's older brother. He distributed the decks amongst a wide array of different people and personalities in order to find the Final Rider, who would take on his representative in the Rider Battle, Kamen Rider Odin.

In truth, he is a tragic villain, a kind man at heart who was broken by loneliness. He orchestrated the entire war for the sake of saving his sister, and accepted her request of ending the useless war.