Myrtil entered military service at the age of 18, first graduating from a special academy, having spent a short time in the service for a conditional 1 year, he returned to his home, but this return turned out to be short-lived.
By 2143-2144, he became one of many witnesses to the outbreak of the First American War, forcing Mackenson to return to service in order to protect his country.
During the full creation of the Alliance, he, like all other new conscripts from different armies, was transferred to the army of the North-South American Alliance.
Even in his last service, Mackenson showed himself in training as an agile and calculating soldier with basic tactical skills.