Terror

Life in [The Pure Trees] was mostly peaceful and busy. Everyone knew about the arrival of the daylight, but no one dared to ruin the relaxed aura that filled the forest at the center of the seven mountains. 

Kelly and the other skeptical recruits eventually had to accept that the new environment brought clear advantages. Their training felt smoother, their improving sensitivity to mana increased their overall awareness, and their constant efforts to control that energy benefited their martial arts in ways that they didn't expect.

Only the manipulation field remained too complicated for most recruits since it belonged to a type of training that was too distant from what the humans believed to be useful.