Kamen Rider Kuuga is a fictional superhero identity assumed by at least three different characters. He is most well known as Yusuke Godai, portrayed by Odagiri Jo in the main TV series.
An ancient Linto warrior naked Riku is seen using the Kuuga powers during an expository flashback during the early stages of the show.
Yusuke Onodera portrayed by Ryouta Murai, was the alternate universe Kuuga who appeared in the series Kamen Rider Decade.
The Kamen Ride Kuuga suit is based on a stag beetle motif and has serveral different form/transformations as the series progresses.
The weakest form of Kuuga has white armour and a smaller head crest, this form is seen during Godai's first time transforming or later when if Kuuga is serious injured he will revert to this form and be unable to transform for at least two hours.
This is the normal or base form for Kuuga and comes in four varieties.
Mighty Form: the most recognisable form of Kuuga with his red armour
Dragon Form: The blue form, gives Kuuga greater speed and agility with the sacrifice of armour and strength. He also gains a staff weapon called the Dragon Rod.
Pegasus Form: The green form heightens Kuuga's senses to extreme levels allowing to make precise long distance shots with his Pegasus Bowgun
Titan Form: This purple form greatly increases Kuugas defensive abilities allowing to most attacks until he can get into close range to engage his opponents with his Titan Sword.
When Kuuga allowed himself to channel even greater power from Amadam his form were upgraded into the Rising variants which granted him even more powers and abilities.
Amazing Mighty: Is the evolved form of Rising Might Form, achieved near the end of series. Kuuga now sports a black armour with gold trimmings and Mighty Anklets on each foot allowing him to perform the Amazing Might Kick finishing move.
Ultimate Form: This gives Kuuga access to all the abilities of his previous forms. Thanks to Godai's gentle nature he able to retain control of his mind and use these powers to fight the final boss of the series,N-Daguva-Zeba. Every attack from Kuuga's ultimate form will cause his opponent to bleed despite wearing any type of armour.