Overall, he cared about his clan above all other things, even his niece Yakumo's life. After the death of herparents, he petitioned with fellow clan members to have Yakumo killed. The Third Hokage denied their requests, and it seems they have given up on them.
Unkai has been shown to be a decisive man, willing to take lethal action against threats towards the Kurama clan, even if this included killing one of his own clansmen, like Yakumo. He cares greatly for the well-being of his clan and has been referred to as a father figure for the clan by Yakumo.
Unkai has light brown hair that falls over his ears. He also has small black eyes.
As a Kurama clan member, he is a very strong genjutsu user, even capable of escaping Kurenai's genjutsu, though having to forfeit his battle with her and retreat. Despite this, he still earned Kurenai's praise.
Unkai proved to have an accomplished leader amongst his fellow clansmen, with them following his directions even if these were against their comrades. Unkai also proved to have a strong sense of smell, using it to pinpoint Kurenai while she was camouflaged.
Yakumo Kurama Rescue Mission
Several years later, Unkai was set on stopping Yakumo once and for all since her unconscious mind held a terrible beast which had killed her parents years earlier. Even though her powers were now sealed away, the beast would only grow over time and threaten the village. With the help of other members of the clan, they began to assault the compound to capture Yakumo. However, Kurenai Yūhi managed to arrive and spirit the young woman away. When Unkai confronted them, Naruto Uzumaki, Sakura Haruno, Hinata Hyūga, Shino Aburame, Kiba Inuzuka, and Might Guy confronted him and caused him to flee. The group was then trapped in Yakumo's genjutsu. He returned to explain to them Yakumo's dark history and helped them escape, suffering burns from Yakumo's powers. After helping Naruto out of the genjutsu which showed a fiery room by having them shut off their mind, Unkai ended up burned. Unkai remained behind to have his burns treated by Sakura and other medical-nin while Naruto and Kurenai confronted Yakumo and helped her come to terms with her powers and put an end to her deadly subconscious.
As with the other members of the Kurama clan, Unkai's first name is related to clouds. In his case, a sea of clouds.