After all, the true form of that 'gazelle' or 'Yang Ying's demon god lies within. Although there's no flesh and blood for it to manipulate as puppets, it might still be possible to replenish a bit of malevolent energy and study the Great Taishu Cosmos Technique developed by Emei.
But if the seal were to be lifted and fail to be resealed, and the 'nonentity' escapes again to destroy the world, or if it were to alert the people of Emei and draw the pursuit of several adversaries who have realized the Dao through cultivation of their divine senses, then Li Fan would really be in trouble.
After all, Li Fan's condition is far too poor now, whether it be the Qiankun Gourd, the Northern Demon God, or the repair of the Taishu Dao body, everything must wait until his condition is restored before he can slowly consider them.