"Yuber (ユーバー, Yūbā?) is a mysterious Black Knight who frequently appears in the midst of conflicts. He openly states that he is not human, and other characters who have come into contact with him remark on his inhuman traits. He bears the Hachifusa Rune, a True Rune of unknown capabilities; while he has the power to summon powerful monsters, such as the Bone Dragon which appeared in Greenhill during the Dunan Unification Wars, it is unclear whether that power stems from the True Rune or some other source. He feels no affection for his employers and works only with them to cause chaos, as evidenced by his desertion of the Highland Kingdom when it becomes clear that they will lose. He harbors a deep hatred toward the True Runes and actively tries to destroy those who wield their power. Little else is known about Yuber or his origins save that he bears a connection to the Black Knight Pesmerga, who pursues Yuber throughout Suikoden and Suikoden II for unknown reasons.
In Suikoden III, Albert Silverberg summons Yuber in order to further his and Luc's plans. Yuber willingly agrees to help them, as Luc's plan will bring about mass chaos and death, both of which he is fond of. After being defeated by the bearer of the True Lightning Rune, however, he once again abandons his employers when their defeat is inevitable."
Source: Wikipedia, "List_of_recurring_characters_in_the_Suikoden_series", available under the CC-BY-SA License.