Among Sacred Knights
Michael had considered adding more Soultrait Symbols to his arsenal but was against it. There was no logical reason not to add anymore Soultraits since his Energy Vortex had expanded drastically after his High Ascension. Other than that, Michael could hunt many more enemies with another 6-Star or higher Soultrait. The energy increase from an additional Soultrait Symbol would be rebalanced by the increase in enemies hunted due to the extra Soultrait.
Still, Michael didn't do it. Why? Because he liked the challenge.
His main body didn't have many challenges left, and the number would dwindle even further once his training period was over. It was a fact which annoyed Michael only a little. Being incredibly powerful was great and all, but having a hard time defeating your opponent was also enticing. Michael couldn't help but feel like he would miss out on something grand if he inserted more Soultraits into his Soul Sphere this soon.