I love you, but I won't love you with my life; I miss you, but I won't miss you every moment; I can give for you, but I won't give everything for you.
—— Pinellia ternata
It wasn't until the end that Nangong Ao understood Banxia's meaning. It's not that Banxia doesn't love him enough, it's that even though he tried his best, he couldn't do it.
Purpose: He lives for him. For him, he was reborn from hell. In this life, he only wants to be with him.