The struggle for control took a drastic turn when Joshua finally discovered and embraced his own power.
Ketis was right all along. Versatility was his greatest strength.
Joshua did not excel in any specific skill or E energy attribute. His conviction and reasons to fight were not as strong or defined as that of his peers.
That did not necessarily mean he was weak.
What he lacked in specialization, he made up for it with versatility.
His exposure to many different design spirits who all specialized in their own E energy attributes and power expressions had allowed Joshua to build up a huge repertoire of techniques and abilities!
Even if he was not able to reproduce them particularly well, it didn't matter so long as he used his strengths to counter the enemy's weaknesses!
It turned out that he did not need to pilot his Everchanger in order to leverage his own versatility.