From what I see now, I believe that "appearance," or say, "Charm," plays an absolutely dominant role.
The Artificial Human Gaslin, who was assigned "Charm," performed very well. He was proficient in manipulating Mandate, hardly seeming like a newcomer who had only been in contact for two hours.
In some sense, this could tentatively prove that Mandate and "Charm" are complementary. The stronger the Charm, the more permissions Mandate will grant to the host, and the host, with the use of Mandate, will also become more skilled, developing more applications of power.
After obtaining the "Gravity" Mandate, Gaslin effortlessly extended his abilities related to "Spacetime." He could halt Spacetime, distort Spacetime to achieve instant teleportation, use Gravity to bend light for invisibility, and control gravity to crush living people into mud... If his Charm were even stronger, perhaps he could stop the rotation of an entire planet?
