Izuka is a character that appears in Fire Emblem: Path of Radiance and Fire Emblem: Radiant Dawn. In Path of Radiance, he serves under King Ashnard, and only appears briefly in a single stage near the end of the game. In Radiant Dawn, however, he takes on a larger role and eventually becomes one of the game's major antagonists.
In Path of Radiance
During his brief appearance in Path of Radiance, Izuka is revealed to be a researcher that serves King Ashnard. A demented individual, he performed dark experiments on laguz in order to create monstrous creatures known as Feral Ones; laguz trapped in their beast forms with their minds twisted and entirely feral. When encountered, he is within the tower in which he had been conducting his experiments. However, with the approach of the Crimean Liberation Army, he quickly flees and goes into hiding.
In Radiant Dawn
Following the events of Path of Radiance, Izuka resurfaces with the young man Pelleas at his side. He claims that Pelleas is in fact the son of Ashnard and his laguz lover, Almedha, and thus the true heir to the Daein throne. Though Izuka's behavior is off-putting to some, Sothe, in particular, he manages to ally Pelleas with the rebels led by Micaiah. This alliance gives the people of Daein hope and the will to drive the Begnion occupation forces from their country.
However, Izuka's claims that Pelleas is the true heir were all lies. Pelleas is not the son of Ashnard nor Almedha. He is a beorc orphan of unknown parentage that became a Spirit Charmer at a young age, and thus bears a brand on his body that could be confused with the mark of the Branded; the children of beorc/laguz pairings. Izuka groomed Pelleas as his pawn and assisted Begnion senators into fooling Pelleas into signing a blood pact, forcing the young king to follow the Begnion senate's orders or suffer the pact's penalty; the death of every Daein citizen.
After Ashera is awakened and delivers her judgment upon the people of Tellius, Izuka goes into hiding in a swampland. There, he is found by an army led by Tibarn, and he makes his final stand through the use of magic and the aid of his Feral Ones. However, he proves no match for Tibarn's forces, and he is killed in battle.