|Title||Gladiator, Warrior, Dragoon|
|Faction||Kingdom of Palatinus/Palantian Revolutionary Army|
Diomedes Rangue, better known by his nickname, Dio, is a playable character in Ogre Battle 64: Person of Lordly Caliber. He initially functions as a rival to protagonist Magnus Gallant, and evolves into either an enemy or a trusted friend depending on the path taken.
Dio was born in the Gunther Piedmont region of Palatinus. When he attempted to join the military he was discriminated against by those who did not share his Southern origin.
Dio is assigned to the same training group as Magnus Gallant, overseen by tactician Hugo Miller. Magnus is made temporary commander for their first mission, which enrages Dio. He ends up challenging Magnus to a fight, with the decision Mangus makes having great impact on their future relationship. Regardless, Hugo dispels the situation, and the two go on to serve two missions together. After the rescue of Prince Yumil Dulmare, Mangus is promoted to captain, and Dio is officially assigned to his battalion, the Blue Knights.
He serves four more missions under Magnus before reaching a crossroads. In most cases, he remains with Magnus when the latter defects to the revolutionary army. In these case, he becomes a close friend to Magnus and the two appear to remain friendly rivals. Dio develops a begrudging respect for Mangus' command abilities.
However, should Mangus respond to Dio's initial challenge in the positive and then proceed to not respond when urged to execute Fredrick Raskin, another scenario takes place. Dio frees Fredrick instead, but escapes the Central Division. He does not return to the Blue Knights afterward. Missions later, he is seen after the defeat of Eurynome Rhade. Rhade had escaped death, but Dio ambushes and kills him.
Dio is apparently given Rhade's place in the Central Division and made a Dragoon after this action, and is later sent to defend the exterior of Fort Romulus from the Blue Knights. It is here he confronts Magnus, and is ultimately killed in battle.