After almost all of the Xianzhou Luofu was entirely infected by mara, Yingxing has been alone. He was cursed by the mara, although he didn't go crazy, the mara-struck gave him the ability to not die, which makes him immortal. He had lost all of his friends, including his master, Dan Feng. But apparently since he reincarnated, as you. He still has deep hatred towards Dan Feng and you for bringing the mara.