Ou Ken has a long goatee with slick, black hair. He is seen with regal court robes which look eccentric and strange.
Ou Ken has a strange personality and an observant mind. Sai Taku describes him as peculiar and difficult to read. He is not above being bought out and sees war as an opportunity to profit greatly. He appears to have a taste for dried snakes as a delicacy.
He is loyal to old friends as he easily recalled his troops when Sai Taku made a better offer. He is also a man of principles as he explained to Ei Sei when meeting him that one of the reasons he withdrew from the Coalition was due to the distaste at the thought of the remaining states devolved into a pack of dogs fighting over scraps after Qin is annihilated.
Due to his experience of residing over a much reduced state of Qi after the first Coalition war, he was convinced that there would be no end to the Warring States if there is no answer to how to end the bloodshed permanently due to the lack of long term effect of perpetual force. It was not until Ei Sei laid out his vision of one kingdom united by laws above both commoners and nobles that he began to see a possible exit to the Warring States Period.
It is assumed that he was the son of the previous Qi king and took the throne after his father's death. He was born in the city of Kyo, one of two remaining cities beside Sokuboku held by Qi during the first Coalition army invasion by Gaku Ki that reduced Qi's power from the superstate it was in the past.
Ou Ken is first seen on the throne, greeting Sai Taku with a grilled poisonous snake in his mouth. Asking why the Qin diplomat is in his court, he listens and informs him of Ri Boku's deal with the other states involved. When Sai Taku offers double, Ou Ken accepts and orders the Qi army to be recalled on the excuse of him taking ill.
Calling Ri Boku a monster, he states that Qin does not have the slightest chance of victory.
It is assumed that he has great political power in the state and can make key decisions for his people.