 He subsequently entered Luoyang (which Western Wei temporarily captured) with Dugu Xin, and for some time tried to defend the city, but eventually they were forced to withdrew from the vicinity of Luoyang.As Wei was then stationed on the borders with Eastern Wei, he became concerned that the Eastern Wei general Niu Daoheng (牛道恆) was capable at drawing the common people of the border region to join Eastern Wei's cause.Wei employed a tactic that he would reuse later—first sending spies to steal samples of Niu's handwriting, and then employing forgers to forge letters purportedly from Niu to Wei offering to defect to Western Wei.