He is a high ranking vampire and the first progenitor from the Warlord Dominion who came to Itogami Island to initially hunt down Christoper Gardos, but it turns out that he actually hired him to activate the Nalakuvera and do battle with it as a means to relive him of boredom, which in the end it was Kojou, Sayaka and Yukina who destroyed it. Though, it was pointed out that he may have some abnormal degree of affection toward Kojou, it is suggested that he is more interested on the Kaleid Blood that flows inside Kojou's veins that was passed on by Avrora than Kojou himself.

After the Nalakuvera incited, he establishes a "Warlord Dominion" consulate at Itogami Island and becomes its consul.

(Source: Anime +)

The Fourth Primogenitor—That's the world's strongest vampire that should only exist in legends. Accompanied by twelve Kenjuu and spreading calamity, this phantom vampire appeared in Japan. For the observation and obliteration of this Fourth Primogenitor, the government and Lion King decided to dispatch an attack mage known as a Sword Shaman. However, for some reason, the one chosen for the observation was a apprentice Sword Shaman girl, Himegari Yukina. Wielding the strongest anti-primogenitor spirit spear, Yukina arrived at Demon District, Itogami City. What is the true identity of the Fourth Primogenitor, Akatsuki Kojou, she encountered over there!? 
(Source: Baka-Tsuki, edited)

[Twitter](https://twitter.com/onoyuki19840622) | [Official Website](http://www.onoyuki.com/) | [Instagram](https://www.instagram.com/onoyuki_official/)

__Height:__ 167cm

Yuuki Ono is a Japanese voice actor and singer who dubs in anime shows and video games. He was represented by Atomic Monkey and is now a freelancer. His major roles are: Josuke Higashikata in JoJo's Bizarre Adventure: Diamond Is Unbreakable, Taiga Kagami in Kuroko's Basketball, Zenkichi Hitoyoshi in Medaka Box, Kaname Tsukahara in Kimi to Boku, Masayuki Hori in Monthly Girls' Nozaki-kun and Ishisaki Jun in Ace of Diamond. 

On October 2, 2017, Ono announced his marriage from the last seven years prior in his blog post. His wife is a person who works outside the entertainment industry. On August 2020, Ono announced the birth of his first child.

**Non-Anime Roles**
- Jiyan - Wuthering Waves (VG)

[Official Website](http://www.henningnoehren.de) | [Synchronkartei](https://www.synchronkartei.de/sprecher/5617/2)

The second season of Strike the Blood. The adaptation of 9th, 11th and 12th LN volumes.

Kojou and Yukina are on their way to school as usual when they find La Folia being chased by someone. Yukina crosses blades with the enormous man who's pursuing her, but before the fight can escalate further, La Folia makes a shocking comment: "Father, this is the Fourth Progenitor, Akatsuki Kojou... my first!" La Folia's father, Lucas, had told her to decide who she wished to marry, so she declares that Kojou is her choice. Lucas refuses to accept this, but then La Folia's mother, Polifonia, invites Kojou and Yukina to a party so they can all talk in more detail. When they arrive at the party, they discover that Asagi, Yaze, Nagisa, and Sayaka have been invited as well, due to their connections with Kojou. What sort of heated battle is about to break out between the many girls in Kojou's life?! 
 
(Source: Crunchyroll)

He never asked for this power.
 
Kojou Akatsuki used to be an ordinary high school boy--but that wasbefore he became the Fourth Primogenitor, the most powerful vampire of all time. Worse--he doesn't even remember how it happened. Middle schooler Yukina Himeragi, meanwhile, is the Attack Mage sent to observe him--and to stop him if he gets out of control. But was it really a good idea to send a cute girl to observe a massively powerful vampire boy whose abilities activate whenever he gets aroused? And on an artificial island populated with all manner of demonic individuals, each with their own designs on the Fourth Primogenitor--?!
 
(Source: Yen Press)

Dimitrie Vatler