Aeno was known for his proudness as a military commander. He was eventually rewarded with the title of main instructor of the Elite Officer School of the Earth Federation.
In UC 0088 when the Instructor Corps launch their rebellion as New Desides, Aeno is tasked with the command of a Federation fleet summoned to help Task Force Alpha in their battle to quickly end the insurrection.
However, unknown to the Federation top brass, Aeno was approached by a member of New Desides. This man, which responded to the name Saotome, convinced Aeno to join the rebel's fight. He defected along with most of his fleet and the Gundam Mk V prototype.
Aeno fought on the battle of Aires city, where he pounded most of Task Force Alpha and Task Force Beta until the Federation sent the main fleet. He lost the battle. Aeno was able to escape the battlefield with his flagship, the Bull's Run and a battered battle cruiser.
He then helped the remains of the New Desides in the conquest of Penta, but surrendered to the Task Force Alpha when the battlecruiser Pegasus III arrived at the space station. He then explained to the pilots of Alpha, that his plight was an attempt to wake up the people to the Federations lost of direction. He hoped that the bloody sacrifice of this campaign changes the state that resulted after AEUG's victory over the Titans with the spacenoids influencing the Earth Federation government.