He knew that Shi Xing didnt kill him because of that. He just said that to comfort the people before their journey…
It's because that time he doesn't know about his powers and his divine activation failed make him say that and his hand was also not working that's why he's saying how can I fight with shi xing but when he reactivated his divine power and his hand was recover he beat the hell out of him ๐ฅ
It's bcz she thinks he's agou that's why treating him like family but when she know that he's Wu geng and they confess there love ,things will change and than they have romantic relation