Yan Yue said this partly to remind Shangguan Zifeng not to shut out those who have the ability to help them, and partly to relieve his own stress. Although the Demon Sect Leader once owed Shangguan Linlang a favor, the Shangguan Clan has now offended the entire Heavenly Dao. Even if Yan Yue wanted to help Shangguan Linlang, his power was ultimately weak. If Shangguan Linlang couldn't gather more capable people, the final outcome might not be very pleasant...
Since Han Ziye is capable and willing to help, why should Shangguan Zifeng resist Han Ziye just because of insignificant pride?
Moreover, even if Shangguan Linlang were present, she should be able to weigh the pros and cons and know how to choose the option that is most beneficial to her.
Yan Yue casually mentioned this, and whether Shangguan Zifeng could accept it was Shangguan Zifeng's worry.
