In 391, Helan Na's brother Helan Rangan () plotted to kill Helan Na, and the brothers engaged in wars against each other. Tuoba Gui took this opportunity to request Later Yan to jointly attacked the Helan tribe—notwithstanding Helan Na and Helan Rangan's status as his uncles. In summer 391, Murong Lin captured Helan Na and Helan Rangan, but allowed Helan Na to remain free and be in command of his tribe, while taking Helan Rangan as a prisoner. It was after this campaign that Murong Lin, seeing Tuoba Gui's abilities, suggested to Murong Chui that Tuoba Gui be detained. Murong Chui refused.