Why did the Hound comply with Beric and decide to help Arya in Game of Thrones S08E03, when Beric pointed at Arya as she was fighting a lot of the dead?
Did the Hound know his role? Did the Lord of Light tell him something about this situation? Did he feel bad for Arya and he decided to help her? Is he sticking to that oath of protecting her?
He didn't want anything to do with the fight, that moment changed his mind and decided to fight for Arya. Is this part explained in the previous seasons about what his role is?