Now that the juregs had been beaten back to the outskirts of the New Cartagena System, Saint Tusa Billingsley-Larkinson enjoyed enough 'free time' to figure out his combat system and build up a proper foundation for himself.
He had already broken through months ago, but it seemed that he had been wasting much of his time while he waited for his Dark Zephyr to get upgraded.
When Tusa looked back on all of the time he spent fighting alongside the expeditionary fleet, he painfully recognized that he had not been doing his best to speed up his progress and work towards his next breakthrough. He still retained a bit of the mentality of an expert pilot and did not think big enough to act like a proper saint.
Just because he remained stuck with an expert mech for a time was not a valid excuse for his lack of progress. There were more ways he could grow stronger than to obsess over his resonance strength.