[Den-O]

DARK KIVA!

No matter what version of him this is (King, Otoya, Taiga) he was entirely too powerful for Dark Kabuto to beat. Even with clock up this is hands down a Dark Kiva victory.

-Access to the same powers as Kiva (i.e. Bashaa, Garuru, Dogga)
-Wake Up One and Two are beastly
-he can create that forcefield Kiva emblem that entraps an enemy
-Taiga as Dark Kiva even has access to his Saga Jacorder which whoops all kinds of ass

This is hands down a Dark Kiva victory. Even if Ryuga was a part of this battle (which he should be by the way) Dark Kiva would still win. Any version of that character is a total badass.