why yuechu is willing to go back can someone explain?
It's because Rong2 told Yuechu that right now Hong2 is burdened by her guilt and responsibilities, that she has no choice but to reject him. So, i guess Yuechu wants to help lessen her burden by returning to his human clan and gain some important position in the human "Yiqi" alliance to fulfill Hong2 wishes of creating peace between human and spirit. If he can gain some power (kind of leader position) in the human alliance, and with Hong2 being the leader of the spirit alliance, they can mantain peace between the two. Then Hong2 will have freedom whether to choose him or not.