N-Daguva-Zeba

N-Daguva-Zeba (ン･ダグバ･ゼバ, N Daguba Zeba) is the stag beetle-like lord of the Gurongi and primary antagonist of Kamen Rider Kuuga. He is given the codenames Unidentified Life Form #0 (未確認生命体第０号, Mikakunin Seimeitai Dai Zero-gō) as his Imperfect Form and Unidentified Life Form B13 (未確認生命体Ｂ群１３号, Mikakunin Seimeitai Bīgun Jūsangō) as his human form.

Personality
Daguva enjoys battle and hates the weak, killing 152 of his own kind for being inferior. He also has a dislike of any of the other Gurongi using his own power for their own, killing both Nu-Zaiju-Re and Zu-Gooma-Gu for using pieces of his discarded armor for their own benefit. He sees Kuuga as the only entertaining challenge for him and takes great enjoyment in in their fight. His goal is to either ensure the plan of the making humanity as violent as the Gurongi is carried out through himself or through Kuuga and is willing to die to see that happen.

Kamen Rider Kuuga
Daguva fought the original Kuuga, Riku, in his Imperfect Form and lost ending up sealed in Kuuga's sarcophagus along with him. He is reawakened in modern times by archaeologists whom he kills and revives the other Gurongi to reinitiate the Gegeru.

Before showing himself to the modern Kuuga, Yuusuke Godai, Daguva kills 152 of his kind seeing them as inferior in Nagano. He reveals himself to the police killing Gooma and falling off the radar after six days of being sighted. By this time he assumed his human form. Once Gadoru is killed, Daguva begins the "end game" by causing an endless heavy rain before defeating Kuuga in his Amazing Mighty Form while leaving massive damage in his wake. As he revealed to Baruba, he is giving Kuuga time to get stronger as a favor for giving him time to move around the country in peace.

Once at Nagano, Daguva resumes the carnage before starting a systematic genocide of all humans in Japan as he tells Yuusuke to meet him at Mount Kuro (九郎ヶ岳, Kurōga-take) for a final confrontation. But as he hoped, Daguva assumes his Gurongi form as he and Kuuga battle each other. After exhausting themselves to the point that they are too weak to maintain their fighting forms, they continue to fight as humans with their bare hands to the death until Daguva finally dies, succumbing from the multiple injuries that he had sustained.

Kamen Rider × Super Sentai: Super Hero Taisen
To be added

Appearance
When first appearing in his Imperfect Form (不完全体, Fukanzentai), Daguva is silohetted and is only seen fully in the S.I.C. series. Daguva's Perfect Form (完全体, Kanzentai) strongly resembles Kamen Rider Kuuga's Ultimate Form but is white in color, adorned with a cape and several Gurongi accessories, and with a smaller head crest. This similar appearance is because of Kuuga's ties to him. Daguva, like most members of his kind, assumes a human form, with his being a white suited young man with an aura.

Abilities
As the Gurongi lord, Daguva has power over his kind through fear. He is very powerful on his own, destroying 152 Gurongi with little effort in his Imperfect Form. He is in possession of an Amadam that increases the user's lifespan. Even in his human form, Daguva gives off a startling aura. His Perfect Form can control heavy rain, blizzard and fire. He is powerful enough to easily defeat Kuuga in his Amazing Mighty Form. He is only matched by Ultimate Kuuga.

Trivia

 * He is similar to Shadow Moon, as they are both evil versions of the main Rider of their respective series, and are not considered Riders themselves.
 * During their final battle, Daguva's and Kuuga's Amadam shattered, reverting them slowly to their human forms. It can be assumed that Daguva had lost his healing ability at that point of time, while Kuuga's Amadam is connected through Gouram. Having his Amadam shattered without a backup, the multiple injuries he sustained were enough to defeat him.