アルティメットフォーム
[[Kamen Rider Kuuga]]'s final form. In this form, he gains a black-colored body with [[spikes]] on the shoulders, forearms and lower part of the legs, a headpiece with [[multiple horns|five horns]], a mouthpiece with sharp, fanged design, and the Amadam stone in the [[rider belt|Arcle]] is now black-colored. The eyes has differing colors as a sign if Kuuga is in full control of his powers in this form or not: [[red eyes|Red]] (similar to Mighty Form) for the former, and [[black eyes|black]] for the latter. 

This form is also the combination of all of Kuuga's previous forms' power without the weaknesses present on them (such as Pegasus Form's sensory overload) and his parameters are much higher, becoming as powerful as [[N-Daguva-Zeba]]. He also has the ability to use any of his previous forms' weapons and possess some abilities that Daguva also uses, such as [[pyrokinesis]], the ability to see human forms of every Gurongi, and the ability to break defenses no matter how strong they are and draw blood in his attacks. It is said that his finishing move, the [i][[rider kick|Ultimate Kick]][/i], can destroy the world if used at full power.

However, using this form puts Kuuga at risk of losing control and becoming a monster bent on destruction like Daguva. It can only be fully controlled if he possess a pure heart. 

Being the first Final Form of the Heisei-era Kamen Riders and beyond, succeeding Riders' Final Forms are also nicknamed "Ultimate Form/s" in its honor.
kamen rider kuuga (ultimate form)