In 431, for reasons not completely clear, Cui and Li Shun appeared to have had a reconciliation, at Cui recommended Li for a mission to Northern Liang, whose prince Juqu Mengxun had recently become a vassal. Upon Li's return, he reported Northern Liang's conditions in great detail, greatly encouraging Emperor Taiwu's plans to conquer Northern Liang. Believing Li to be capable, Emperor Taiwu also made him a major advisor, and Li and Cui appeared to resume their rivalry from this point on.