Viewed by the world as a ruthless killer, he has an ugly scar on his face because his cruel brother pushed him into a fire when he was a child. In fact, he still has a trace of humanity and kindness in his heart.
He left the capital, met the adventurous Arya, and adventured with her in the Seven Kingdoms until he met Brienne and was seriously injured in the fight.
He was rescued by nearby villagers and embarked on the road of revenge.