During the Clone Wars, Gandon Belak was a haughty young man with a severe lust for battle. He was a fierce warrior, having served with Locke until the Mandalorians were nearly wiped out. However, his lust for battle and overeagerness to fight never clouded his judgements, and he never made a mistake he couldn't walk away from.
When the Jedi all but wiped out the Mandalorians, Gandon held a severe grudge against the Force-and-lightsaber wielders of "peace and justice". However, instead of seeking his revenge, he obediently followed orders and went back to Mandalore, with Locke, in preparation for another great Mandalorian Crusade, something not witnessed for thousands of years.
Due to his ability to follow orders and abide by the bound-by-honor code that the Mandalorians swear to, Gandon is the primary instructor for new recruits for the next breed of the fierce Mandalorian Warriors.
As such, he was successful in turning a group of limited-to-no-fighting-experience individuals into fierce warriors and "almost warriors", capable of looking into the face of death and still fighting to their very last breath. The first breed of shock troopers received all their training directly from Gandon, and the first breed of supercommandos also received their basic training from him as well, going on to be trained directly by Mandalore Cadden Blackthorne.