I have only read till the start of the beast kingdom arc so I don't know how much happens to the characters but here I go.
I have to say that the character that made me go from liking the novel to loving it was Swordmad. He is a true warrior nice guy that is honest and determined to hilarious extremes yet quite jaded by fate by people weaker than him making a kill move on someone he cares about just when he's too far to save them until Yale that could "survive" due to time element. But he stayed with the clan seemingly because he wanted to care for something but not someONE as would happen if he went to the academy to teach and would likely take more disciples only to watch them die. He has a level of nuance between vulnerability and badassness that makes him main character material honestly. Kind want there to be a reincarnation story about him next.:D